JP2009200405A - Semiconductor manufacturing apparatus and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To regulate the oxidation degree of an IrOx film without periodical check of a test sample. <P>SOLUTION: A semiconductor manufacturing apparatus for manufacturing a semiconductor device having a ferroelectric capacitor including an upper electrode, a dielectric, and a lower electrode, an inlet for introducing an oxygen gas contained in a gas mixture for forming the upper electrode on the semiconductor wafer placed in a film forming chamber to the chamber, A regulator for regulating oxygen gas introduced into the film forming chamber, and a measuring part for measuring an oxygen gas concentration contained in the mixed oxygen gas in the film forming chamber. When the gas concentration measured by the measuring part is not within a prescribed range, the regulator controls the amount of oxygen gas to be introduced so that the gas concentration falls within the prescribed range. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor manufacturing apparatus and a semiconductor device manufacturing method.

Nonvolatile semiconductor memory circuit (FeRAM: Ferroelectric Random) using ferroelectric material
The upper electrode of the ferroelectric capacitor of Access Memory is formed by laminating two types of IrOx films having different degrees of oxidation. An IrOx film is formed on a semiconductor wafer (hereinafter simply referred to as a wafer) by introducing a mixed gas of Ar gas and O ₂ gas (oxygen gas) into the film forming chamber and performing reactive sputtering using an Ir target. Has been done. The degree of oxidation of the IrOx film on the upper layer of the upper electrode has a great influence on the characteristics of the ferroelectric capacitor. Therefore, it is important to control the degree of oxidation of the IrOx film on the upper layer of the upper electrode.
JP 2006-73648 A Japanese Patent Laid-Open No. 2004-39699 JP 2006-222136 A

  When controlling the degree of oxidation of the IrOx film on the upper layer of the upper electrode, there is a method of checking the degree of oxidation of the IrOx film by periodically checking a test sample (test piece) after the IrOx film is formed. When the test sample after the IrOx film is formed is periodically checked and the degree of oxidation of the IrOx film is confirmed, a step of checking the test sample is required. Moreover, it is necessary to prepare a test sample itself. An object of the present invention is to provide a technique for controlling the degree of oxidation of an IrOx film without the need to periodically check a test sample.

  The present invention employs the following means in order to solve the above problems. That is, the semiconductor manufacturing apparatus of the present invention is a semiconductor manufacturing apparatus for manufacturing a semiconductor device having a ferroelectric capacitor composed of an upper electrode, a dielectric, and a lower electrode, and a semiconductor wafer installed in a film forming chamber. An introduction part for introducing oxygen gas contained in a mixed gas for forming the upper electrode into the film formation chamber, a control part for controlling an introduction flow rate of oxygen gas introduced into the film formation chamber, A measurement unit that measures the concentration of oxygen gas contained in the mixed gas in the membrane chamber, and the control unit has a concentration value of oxygen gas measured by the measurement unit not within a predetermined value range In this case, the flow rate of the oxygen gas is changed so that the value of the oxygen gas concentration falls within a predetermined value range.

  According to the semiconductor manufacturing apparatus of the present invention, when the oxygen gas concentration value is not within the predetermined value range, the oxygen gas is introduced into the film forming chamber so that the oxygen gas concentration value is within the predetermined value range. Change the flow rate. Then, by changing the flow rate of oxygen gas introduced into the film formation chamber, the concentration of oxygen gas contained in the mixed gas in the film formation chamber is controlled to be within a predetermined value range. Such control makes it possible to manufacture a semiconductor device having a ferroelectric capacitor having desired capacitor characteristics. Further, the present invention may be a method in which a computer, other devices, machines, etc. execute any one of the processes described above.

  According to the present invention, the degree of oxidation of the IrOx film can be controlled without having to periodically check the test sample.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the following embodiment is an exemplification, and the present invention is not limited to the configuration of the embodiment.

A ferroelectric capacitor includes a lower electrode, a dielectric, and an upper electrode. The lower electrode has a laminated structure of, for example, an Al ₂ O ₃ (aluminum oxide) film and a Pt film. The dielectric is made of, for example, PZT (lead zirconate titanate) which is a ferroelectric. The upper electrode is formed of, for example, an IrOx (iridium oxide) film.

As shown in FIG. 1, when an IrOx film is formed on a wafer (semiconductor substrate) 3 placed on a wafer stage 2 in a film forming chamber 1, a mixed gas of Ar gas and O ₂ gas is supplied to the film forming chamber 1. Introduce. Then, plasma excitation is performed using the Ir target 5 installed on the backing plate 4 as a cathode, and argon ions (Ar ⁺ ) are generated. Argon ion (
When Ar ⁺ ) collides with the Ir target 5, Ir atoms are ejected, and an IrOx film is formed on the wafer 3 placed oppositely. In the film forming chamber 1, a shield (a deposition plate) 6 is provided between the inner wall of the film forming chamber 1 and the wafer 3.

  The degree of oxidation of the IrOx film correlates with the reflectance and sheet resistance of the IrOx film. As the degree of oxidation of the IrOx film increases, the reflectance of the IrOx film tends to decrease. As the degree of oxidation of the IrOx film increases, the sheet resistance of the IrOx film tends to increase. Therefore, the degree of oxidation of the IrOx film can be indirectly recognized by measuring the reflectance of the IrOx film. Further, the degree of oxidation of the IrOx film can be indirectly recognized by measuring the sheet resistance of the IrOx film.

FIG. 2 shows the relationship between the switching polarization amount and the reflectance of the IrOx film. The vertical axis in FIG. 2 is the amount of switching polarization (coulomb / cm ² ), and the horizontal axis in FIG. 2 is the reflectance (%) of the IrOx film. In FIG. 2, the amount of switching polarization is measured when the reflectance of the IrOx film is 25%, 26%, and 27%. Further, the switching polarization amount is measured the same number of times when the reflectance of the IrOx film is 25%, 26%, and 27%.

When the reflectance of the IrOx film is 25%, the switching polarization amount is in the range of about 2.4E-05 (2.4 × 10 ⁻⁵ ) to 2.6E-05 (2.6 × 10 ⁻⁵ ). is there. When the reflectance of the IrOx film is 26%, the switching polarization amount is in the range of about 1.8E-05 (1.8 × 10 ⁻⁵ ) to 2.2E-05 (2.2 × 10 ⁻⁵ ). is there. When the reflectance of the IrOx film is 27%, the switching polarization amount is in the range of about 1.6E-05 (1.6 × 10 ⁻⁵ ) to 1.8E-05 (1.8 × 10 ⁻⁵ ). is there. Thus, it can be seen that the amount of switching polarization increases as the reflectance of the IrOx film decreases. As the amount of switching polarization increases, the read margin of FeRAM also increases.

  FIG. 3 shows the relationship between the leakage current and the reflectance of the IrOx film. The vertical axis in FIG. 3 is the leakage current (A), and the horizontal axis in FIG. 3 is the reflectance (%) of the IrOx film. The leak current shown in FIG. 3 is a leak current between the upper electrode of the ferroelectric capacitor and the dielectric. In FIG. 3, the leakage current is measured when the reflectance of the IrOx film is 25%, 26%, and 27%. Further, the leak current is measured the same number of times when the reflectance of the IrOx film is 25%, 26%, and 27%.

When the reflectance of the IrOx film is 25%, the leakage current is in the range of about 5.0E-09 (5.0 × 10 ⁻⁹ ) to 3.5E-09 (3.5 × 10 ⁻⁸ ). . When the reflectance of the IrOx film is 26%, the leakage current is 1.0E-08 (1.0 × 10 ⁻⁸ ) to 2.0E-08 (2.0
It is in the range of about × 10 ^-8 ). When the reflectance of the IrOx film is 27%, the leakage current is in the range of about 1.0E-08 (1.0 × 10 ⁻⁸ ) to 2.0E-08 (2.0 × 10 ⁻⁸ ). .

  As shown in FIG. 3, when the reflectance of the IrOx film is decreased, the distribution of the leakage current tends to be wide, and the leakage current may be increased. When the leakage current increases, the retention characteristic (data retention capability) of the ferroelectric capacitor deteriorates.

  A smaller reflectance of the IrOx film is desirable from the viewpoint of the amount of switching polarization, but if the reflectance of the IrOx film is too small, it is not desirable from the viewpoint of the retention characteristics of the ferroelectric capacitor. Therefore, the reflectance of the IrOx film is desired to be a value that can suppress the leakage current and does not increase the switching polarization amount so much. It can be said that the reflectance value of the IrOx film satisfying such a requirement is 26% from FIG. 2 and FIG.

FIG. 4 shows the relationship between the O ₂ gas flow rate and the reflectance of the IrOx film when forming the IrOx film, and the relationship between the O ₂ gas flow rate and the sheet resistance of the IrOx film when forming the IrOx film. Here, the O ₂ gas flow rate in the case of forming the IrOx film, a flow rate of O ₂ gas to be introduced into the film forming chamber 1. In FIG. 4, the O ₂ gas flow rate (sccm) when an IrOx film is formed on the horizontal axis.
The vertical axis (left side) shows the reflectance (%) of the IrOx film, and the vertical axis (right side) shows the sheet resistance (Ω) of the IrOx film.

When the flow rate of O ₂ gas when the IrOx film is formed is changed, the degree of oxidation of the IrOx film after the film formation is changed. When the degree of oxidation of the IrOx film after film formation changes, the reflectance and sheet resistance of the IrOx film change.

As shown in FIG. 4, when the flow rate of O ₂ gas when forming the IrOx film is 40 sccm, the reflectance of the IrOx film exceeds 28%, and the sheet resistance of the IrOx film is about 25.5Ω. . As shown in FIG. 4, the flow rate of O ₂ gas when forming an IrOx film is 60 sc.
When cm, the reflectivity of the IrOx film is about 25%, and the sheet resistance of the IrOx film exceeds 70Ω. Thus, when the O ₂ gas flow rate when forming the IrOx film is increased,
The reflectivity of the IrOx film decreases and the sheet resistance of the IrOx film increases.

In the case of manufacturing a ferroelectric capacitor so that the reflectance of the IrOx film becomes 26%, considering the relationship of FIG. 4, the flow rate of O ₂ gas when forming the IrOx film should be 55 sccm. Become.

In the process of forming the IrOx film on the wafer 3, the IrOx film is also formed on the inner wall surface of the shield 6 installed in the film forming chamber 1. The IrOx film formed on the inner wall surface of the shield 6 releases O ₂ gas as degassing. Therefore, if O ₂ gas is introduced into the film forming chamber 1 in a state where the IrOx film is formed on the shield 6, the O ₂ gas concentration in the film forming chamber 1 increases. The O ₂ gas concentration refers to the proportion of O ₂ gas contained in the mixed gas of Ar gas and O ₂ gas. In a state where the O ₂ gas concentration in the film forming chamber 1 is increased, IrO is applied to the wafer 3.
When the x film is formed, the reflectance of the IrOx film decreases and the sheet resistance of the IrOx film increases. Therefore, when an IrOx film is formed on the wafer 3 in a state where the O ₂ gas concentration in the film forming chamber 1 is increased, the degree of oxidation is increased.

FIG. 5 shows the relationship between the reflectance of the IrOx film and the shield life. The shield life is the amount of power (kWh) supplied to the Ir target 5 when forming the IrOx film. The shield life can also be said to be an integrated processing time when forming the IrOx film. The vertical axis in FIG. 5 is the reflectance (%) of the IrOx film, and the horizontal axis in FIG. 5 is the shield life (kWh). Here, when an IrOx film is formed on the wafer 3, O ₂ introduced into the film forming chamber 1 is used.
The flow rate of gas is 59 sccm, and the flow rate of Ar gas introduced into the deposition chamber 1 is 100 sccm. As shown in FIG. 5, as the shield life increases, the reflectance of the IrOx film tends to decrease, and the decrease in the reflectance of the IrOx film depends on the increase in the shield life. As shown in FIG. 5, as the shield life increases, the reflectivity of the IrOx film decreases. Therefore, it can be seen that the oxidation degree of the IrOx film increases as the shield life increases.

FIG. 6 shows the relationship between the sheet resistance of the IrOx film and the shield life. The vertical axis in FIG. 6 is the sheet resistance (Ω) of the IrOx film, and the horizontal axis in FIG. 6 is the shield life (kWh). Here, when an IrOx film is formed on the wafer 3, the flow rate of O ₂ gas introduced into the deposition chamber 1 is 59 sccm, and the flow rate of Ar gas introduced into the deposition chamber 1 is 10
0 sccm. As shown in FIG. 6, as the shield life increases, the sheet resistance of the IrOx film tends to increase, and the increase in the sheet resistance of the IrOx film depends on the increase in the shield life. As shown in FIG. 6, as the shield life increases, the sheet resistance of the IrOx film increases. Therefore, it can be seen that the oxidation degree of the IrOx film increases as the shield life increases.

FIG. 7 shows the relationship between the shield life and the flow rate of O ₂ gas when forming an IrOx film. FIG. 7 shows that the test sample after forming the IrOx film is periodically checked, and the flow rate of O ₂ gas when forming the IrOx film is decreased based on the result of measuring the reflectance and sheet resistance of the IrOx film. 3 shows the relationship between the shield life at the time of the deposition and the O ₂ gas flow rate in the case of forming an IrOx film. The vertical axis in FIG. 7 is the O ₂ gas flow rate when forming an IrOx film, and the horizontal axis in FIG. 7 is the shield life. Curves A, B, and C in FIG. 7 periodically check the test sample after forming the IrOx film under the same conditions, measure the reflectance and sheet resistance of the IrOx film, and form the IrOx film. This is the relationship between the shield life when the O ₂ gas flow rate is reduced and the O ₂ gas flow rate when forming the IrOx film.

In the example of the curve in FIG. 7, when the shield life is 10 kWh, the O ₂ gas flow rate when the IrOx film is formed is controlled to about 51.0 sccm. In the example of curve B in FIG. 7, when the shield life is 10 kWh, the O ₂ gas flow rate when forming the IrOx film is about 53.5 sc.
It is controlled to cm. In the example of curve C in FIG. 7, when the shield life is 10 kWh, the O ₂ gas flow rate when the IrOx film is formed is controlled to about 55.0 sccm. As described above, the O ₂ gas flow rate when forming the IrOx film cannot be uniquely determined from the value of the shield life.

As the O ₂ gas concentration in the deposition chamber 1 increases, the degree of oxidation of the IrOx film increases. Therefore, the IrOx film is applied to the wafer 3 while maintaining the O ₂ gas concentration in the deposition chamber 1 constant. It is necessary to form a film. Therefore, the oxidation degree of the IrOx film after film formation is stabilized by forming an IrOx film on the wafer 3 while maintaining the O ₂ gas concentration in the film formation chamber 1 constant.

<First Embodiment>
FIG. 8 is a diagram showing an example of the structure of the semiconductor manufacturing apparatus 10 according to the first embodiment. In the film forming chamber 1, a wafer 3 is placed on the wafer stage 2, and an Ir target 5 is placed on the backing plate 4 so as to face the wafer 3. In order to prevent the IrOx film from being formed on the inner wall surface of the film forming chamber 1 when the IrOx film is formed on the wafer 3, a shield (a deposition plate) 6 is provided in the film forming chamber 1. .

The film-forming chamber 1, O ₂ gas concentration meter 11 for measuring the O ₂ concentration of O ₂ gas is connected via a pipe 12. Data of the O ₂ concentration of O ₂ gas to be measured by the O ₂ gas concentration meter 11 is sent to the O ₂ gas concentration meter 11 is electrically connected to the control unit 13.
As the O ₂ gas concentration meter 11, for example, a zirconia oxygen concentration meter can be used. The control unit 13 includes a CPU, a ROM, and the like inside, and the CPU executes various processes according to a control program recorded in the ROM.

As shown in FIG. 8, the pipe 12 is connected to the film forming chamber 1 so that one end of the pipe 12 opens near the wafer stage 2 in the film forming chamber 1. Therefore, the O ₂ gas concentration meter 11 can measure the concentration of O ₂ gas contained in the gas existing around the wafer 3 installed on the wafer stage 2 via the pipe 12. In this way, by measuring the concentration of O ₂ gas contained in the gas existing around the wafer 3, the O ₂ gas concentration that is highly likely to affect the quality of the IrOx film actually formed is measured. can do.

The control unit 13 is electrically connected to an O ₂ gas introduction device 14 that introduces O ₂ gas into the film forming chamber 1. The control unit 13 controls the flow rate of O ₂ gas introduced into the film forming chamber 1 by controlling the O ₂ gas introduction device 14. Further, not limited to this, instead of the O ₂ gas introduction apparatus 14 O ₂ gas with the O ₂ gas cylinder, which is filled by O ₂ controlling the opening of the gas cylinder of the valve unit 13 is controlled, the deposition chamber The flow rate of O ₂ gas introduced into 1 may be controlled.

  The control unit 13 is electrically connected to an Ar gas introduction device 15 that introduces Ar gas into the film forming chamber 1. The control unit 13 controls the flow rate of Ar gas introduced into the film forming chamber 1 by controlling the Ar gas introduction device 15. The present invention is not limited to this, and an Ar gas cylinder filled with Ar gas is provided instead of the Ar gas introduction device 15, and the control unit 13 controls the opening degree of the valve of the Ar gas cylinder so that it is introduced into the film forming chamber 1. The flow rate of Ar gas may be controlled.

  FIG. 9 is a diagram illustrating an example of the structure of the semiconductor manufacturing apparatus 10 according to the first embodiment. The semiconductor manufacturing apparatus 10 shown in FIG. 9 differs from the semiconductor manufacturing apparatus 10 shown in FIG. 8 in the position of the pipe 16 connected to the film forming chamber 1. The other configuration is the same as that of the semiconductor manufacturing apparatus 10 shown in FIG. 8, and the description of the same configuration is omitted.

As shown in FIG. 9, the pipe 16 is connected to the film forming chamber 1 so that one end of the pipe 16 opens at the inner wall of the shield 6 provided in the film forming chamber 1. Therefore, the O ₂ gas concentration meter 11 can measure the O ₂ gas concentration contained in the gas existing around the inner wall surface of the shield 6 through the pipe 16. In other words, the O ₂ gas concentration meter 11 can measure the O ₂ gas concentration contained in the gas existing on the inner wall surface of the shield 6 through the pipe 16. The degree of oxidation in the film forming chamber 1 is affected by the O ₂ gas released as degassing by the IrOx film formed on the inner wall surface of the shield 6. By measuring the concentration of O ₂ gas contained in the gas existing around the inner wall surface of the shield 6, the O ₂ gas released from the IrOx film formed on the inner wall surface of the shield 6 as degassing is taken into consideration. , O ₂ gas concentration can be measured.

The control unit 13 controls the O ₂ gas introduction device 14 based on the value of the O ₂ gas concentration measured by the O ₂ gas concentration meter 11 to increase or decrease the flow rate of the O ₂ gas introduced into the film forming chamber 1. Let Specifically, the control unit 13 controls the O ₂ gas introduction device 14 so that the value of the O ₂ gas concentration measured by the O ₂ gas concentration meter 11 falls within the range of the predetermined value C, and the film formation chamber. The flow rate of the O ₂ gas introduced into 1 is reduced or increased.

Accordingly, the control unit 13 sets the value of the O ₂ gas flow rate as O ₂ initial value to the gas introduction device 14, based on the value of the O ₂ gas concentration measured by the O ₂ gas concentration meter 11, O ₂
Processing for changing the value of the O ₂ gas flow rate set as the initial value in the gas introducing device 14 is performed. Further, the control unit 13 changes the value of the O ₂ gas flow rate set as the initial value in the O ₂ gas introduction device 14 and then based on the value of the O ₂ gas concentration measured by the O ₂ gas concentration meter 11. , O ₂
A process of changing the value of the O ₂ gas flow rate set in the gas introducing device 14 is performed.

The processing of the control unit 13 will be described with reference to FIG. 10, the control unit 13, based on the value of the O ₂ gas concentration measured by the O ₂ gas concentration meter 11, controlling the O ₂ gas introduction device 14, O ₂ gas introduced into the film forming chamber 1 It is a flowchart which shows the flow of the process which changes the flow volume of this. The control unit 13 starts the process shown in FIG. 10 after the wafer 3 is placed on the wafer stage 2 in the film forming chamber 1 and the preparation of the film forming process for the wafer 3 is completed.

First, the control unit 13 sets an O ₂ gas flow rate value as an initial value in the O ₂ gas introduction device 14 (S101). Further, the control unit 13 sets the Ar gas flow rate value in the Ar gas introduction device 15. The value of the Ar gas flow rate set in the Ar gas introduction device 15 is a fixed value, but may be changed as appropriate.

Next, after the film forming process of the wafer 3 is started, the control unit 13 reads the O ₂ gas concentration meter 1.
1 acquires the data of the O ₂ gas concentration measured from the O ₂ gas concentration meter 11 (S102). Then, the control unit 13 determines whether or not the value of the O ₂ gas concentration acquired from the O ₂ gas concentration meter 11 is within the range of the predetermined value C (S103).

When the value of the O ₂ gas concentration acquired from the O ₂ gas concentration meter 11 is within the range of the predetermined value C (YES in the process of S103), the control unit 13 determines whether or not the film forming process of the wafer 3 has been completed. Is confirmed (S104). If the film forming process for the wafer 3 has been completed, the control unit 13 proceeds to the process of S102 after the film forming process for the next wafer 3 is started. Here, the next wafer 3 refers to a wafer 3 that has been transferred into the film formation chamber 1 and has not yet been processed after the wafer 3 that has been subjected to the film formation process has been removed from the film formation chamber 1. Then, the control unit 13 performs the processing after S102 on the next wafer 3. If the film forming process for the wafer 3 has not been completed, the control unit 13 proceeds to the process of S102. Then, the control unit 13 performs the processes after S102 on the wafer 3 for which the film forming process has not been completed.

On the other hand, if the value of the O ₂ gas concentration obtained from the O ₂ gas concentration meter 11 is not within the predetermined value C (NO in the processing of S103), the control unit 13, is set to O ₂ gas introduction device 14 The value of the O ₂ gas flow rate is changed (S105).

Specifically, the value of the O ₂ gas concentration obtained from the O ₂ gas concentration meter 11 is larger than the predetermined value C, the control unit 13, the O ₂ gas flow rate is set to O ₂ gas introduction device 14 Decrease the value. When the value of the O ₂ gas concentration obtained from the O ₂ gas concentration meter 11 is smaller than the predetermined value C, the control unit 13, increments the value of the O ₂ gas flow rate is set to O ₂ gas introduction device 14 Let For example, the control unit 13 changes the amount of change (increase / decrease) in the value of the O ₂ gas flow rate set in the O ₂ gas introduction device 14 from a map showing the relationship between the O ₂ gas concentration and the O ₂ gas flow rate. You may make it ask. A map showing the relationship between the O ₂ gas concentration and the O ₂ gas flow rate may be recorded in the control unit 13 in advance.

After changing the value of the O ₂ gas flow rate set in the O ₂ gas introduction device 14, the control unit 13 proceeds to the process of S104.

The predetermined value C may be recorded in the control unit 13. For example, a value of 35.5% to 36.3% is recorded in the control unit 13 as the predetermined value C. As O ₂ gas concentration of the film forming chamber 1 is in the range of 35.5% ~36.3%, O ₂ is introduced into the film forming chamber 1
By controlling the gas flow rate, it is possible to manufacture a ferroelectric capacitor in which the reflectance of the IrOx film is about 26%. It is more preferable to control the flow rate of O ₂ gas introduced into the film forming chamber 1 so that the O ₂ gas concentration in the film forming chamber 1 is 35.9%. However,
The value of the O ₂ gas concentration described as an example of the predetermined value C varies depending on the conditions for manufacturing the ferroelectric capacitor, and these values can be appropriately changed depending on the conditions for manufacturing the ferroelectric capacitor. It is.

In this way, the O ₂ gas concentration in the film forming chamber 1 is automatically measured, and the flow rate of the O ₂ gas introduced into the film forming chamber 1 is controlled based on the measurement result, whereby the IrOx film on the wafer 3 is controlled. Can be controlled within a desired range. By controlling the reflectance of the IrOx film on the wafer 3 within a desired range, the degree of oxidation of the IrOx film on the wafer 3 can be stabilized.

Second Embodiment
FIG. 11 is a diagram illustrating an example of the structure of the semiconductor manufacturing apparatus 10 according to the second embodiment. The semiconductor manufacturing apparatus 10 according to the second embodiment includes a wafer 3 before film formation processing, a wafer carrier 21 for storing the wafer 3 after film formation processing, a wafer aligner 22 for aligning the wafer 3, and a vacuum. A load lock chamber 23 for evacuating, a film forming chamber 1 for performing a film forming process for the wafer 3, a transfer chamber 24 provided between the load lock chamber 23 and the film forming chamber 1, and a wafer 3 for transferring. The transfer robots 25 and 26 are provided.

  The transfer robot 25 transfers the wafer 3 between the wafer carrier 21, the wafer aligner 22, and the load lock chamber 23. The transfer robot 26 is provided in the transfer chamber 24 and transfers the wafer 3 between the load lock chamber 23, the transfer chamber 24, and the film forming chamber 1.

  The wafer aligner 22 is provided with a stage (not shown). The wafer 3 is placed on the stage of the wafer aligner 22 and the wafer 3 is aligned. The wafer aligner 22 is provided with a detection sensor 27, and the detection sensor 27 detects whether or not the wafer 3 is installed on the stage of the wafer aligner 22.

  The wafer aligner 22 is provided with a reflectance measurement device and a resistance measurement device (not shown). The reflectance measuring apparatus measures the reflectance of the IrOx film formed on the wafer 3 installed on the stage of the wafer aligner 22. The resistance measuring device measures the sheet resistance of the IrOx film formed on the wafer 3 installed on the stage of the wafer aligner 22.

Although not shown in FIG. 11, the semiconductor manufacturing apparatus 10 according to the second embodiment includes the control unit 13, the O ₂ gas introduction device 14, and the Ar gas introduction device 15 in the same manner as the semiconductor manufacturing apparatus 10 according to the first embodiment. I have. The control unit 13 is electrically connected to the O ₂ gas introduction device 14 and the Ar gas introduction device 15, respectively. The control unit 13 is electrically connected to the reflectance measuring device and the resistance measuring device, respectively, and controls the reflectance measuring device and the resistance measuring device. The control unit 13 receives data on the reflectance of the IrOx film measured by the reflectance measuring device from the reflectance measuring device. The control unit 13 receives data of the sheet resistance of the IrOx film measured by the resistance measuring device from the resistance measuring device.

The control unit 13 controls the O ₂ gas introduction device 14 based on the value of the reflectance of the IrOx film measured by the reflectance measurement device, and increases or decreases the flow rate of the O ₂ gas introduced into the film forming chamber 1. . Specifically, the control unit 13 controls the O ₂ gas introducing device 14 so that the reflectance value of the IrOx film measured by the reflectance measuring device is within a predetermined value R, and the film forming chamber 1 The flow rate of the O ₂ gas introduced into is reduced or increased. Further, the control unit 13, O ₂ where the reflectance of the IrOx film to be measured by the reflectance measurement device controls the O ₂ gas introduction device 14 to a predetermined value R, it is introduced into the film forming chamber 1 The gas flow rate may be reduced or increased. The predetermined value R may be recorded in the control unit 13 in advance.

Accordingly, the control unit 13 sets the value of the O ₂ gas flow rate as an initial value of O ₂ gas introduction device 14, based on the value of the reflectance of the IrOx film to be measured by the reflectance measurement device, O ₂ gas A process of changing the value of the O ₂ gas flow rate set as the initial value in the introducing device 14 is performed. Further, the control unit 13 changes the value of the O ₂ gas flow rate set as the initial value in the O ₂ gas introduction device 14, and then, based on the reflectance value of the IrOx film measured by the reflectance measuring device, A process of changing the value of the O ₂ gas flow rate set in the O ₂ gas introduction device 14 is performed.

Specifically, when the reflectance value of the IrOx film measured by the reflectance measuring device is larger than a predetermined value R, the control unit 13 sets the O ₂ gas flow rate set in the O ₂ gas introduction device 14. Increase the value. When the reflectance value of the IrOx film measured by the reflectance measuring device is smaller than the predetermined value R, the control unit 13 decreases the value of the O ₂ gas flow rate set in the O ₂ gas introduction device 14. Let For example, the control unit 13 shows a change amount (increase / decrease amount) of the value of the O ₂ gas flow rate set in the O ₂ gas introduction device 14 and a map showing the relationship between the reflectance of the IrOx film and the O ₂ gas flow rate. You may make it ask from. A map showing the relationship between the reflectance of the IrOx film and the O ₂ gas flow rate may be recorded in the control unit 13 in advance.

The control unit 13 controls the O ₂ gas introduction device 14 based on the value of the sheet resistance of the IrOx film measured by the resistance measurement device, and increases or decreases the flow rate of the O ₂ gas introduced into the film forming chamber 1. Specifically, the control unit 13 controls the O ₂ gas introduction device 14 so that the value of the sheet resistance of the IrOx film measured by the resistance measurement device is within the range of the predetermined value S. Reduce or increase the flow rate of the introduced O ₂ gas. Further, the control unit 13, the O ₂ gas the value of the sheet resistance of the IrOx film to be measured by the resistance measuring device controls the O ₂ gas introduction device 14 to a predetermined value S, is introduced into the film forming chamber 1 The flow rate may be decreased or increased. The predetermined value S may be recorded in the control unit 13 in advance.

Accordingly, the control unit 13, O ₂ in the gas introduction device 14 sets the value of the O ₂ gas flow rate as an initial value, based on the value of the sheet resistance of the IrOx film to be measured by the resistance measuring device, O ₂ gas introduction A process of changing the value of the O ₂ gas flow rate set as the initial value in the apparatus 14 is performed. Further, the control unit 13 changes the value of the O ₂ gas flow rate set as the initial value in the O ₂ gas introduction device 14 and then changes the O ₂ gas flow rate based on the sheet resistance value of the IrOx film measured by the resistance measurement device. _{2 The} process of changing the value of the O ₂ gas flow rate set in the gas introduction device 14 is performed.

Specifically, when the value of the sheet resistance of the IrOx film measured by the resistance measuring device is larger than the predetermined value S, the control unit 13 sets the value of the O ₂ gas flow rate set in the O ₂ gas introducing device 14. Decrease. When the sheet resistance value of the IrOx film measured by the resistance measuring device is smaller than the predetermined value S, the control unit 13 increases the value of the O ₂ gas flow rate set in the O ₂ gas introducing device 14. . For example, the control unit 13 is a map showing the change amount (increase / decrease amount) of the O ₂ gas flow rate set in the O ₂ gas introduction device 14 and the relationship between the sheet resistance of the IrOx film and the O ₂ gas flow rate. You may make it ask from. A map showing the relationship between the sheet resistance of the IrOx film and the O ₂ gas flow rate may be recorded in the control unit 13 in advance.

Thus, by automatically measuring the reflectance and sheet resistance of the IrOx film deposited on the wafer 3, and controlling the flow rate of O ₂ gas introduced into the deposition chamber 1 based on the measurement results, The reflectance and sheet resistance of the IrOx film on the wafer 3 can be controlled within a desired range. By controlling the reflectance and sheet resistance of the IrOx film on the wafer 3 within a desired range, the degree of oxidation of the IrOx film on the wafer 3 can be stabilized.

  A process of measuring the reflectance and sheet resistance of the IrOx film formed on the wafer 3 will be described with reference to FIG. FIG. 12 is a flowchart showing the flow of processing for measuring the reflectance and sheet resistance of the IrOx film formed on the wafer 3.

  First, the transfer robot 25 takes out the wafer 3 stored in the wafer carrier 21 (S201). Next, the transfer robot 25 transfers the taken wafer 3 to the wafer aligner 22 and places it on the stage of the wafer aligner 22 (S202). By aligning the wafer 3 placed on the stage of the wafer aligner 22 in the horizontal direction, the wafer 3 is aligned (aligned). For example, in the wafer aligner 22, the presence or absence of an orientation flat or notch is confirmed by an optical sensor, and the wafer 3 is aligned.

  After the alignment of the wafer 3 is performed, the transfer robot 25 transfers the wafer 3 into the load lock chamber 23 (S203). The wafer 3 transferred into the load lock chamber 23 is installed in the load lock chamber 23. Thereafter, the load lock chamber 23 is evacuated, and the gate valve 28 provided between the load lock chamber 23 and the transfer chamber 24 is opened.

  The transfer robot 26 transfers the wafer 3 installed in the load lock chamber 23 into the film forming chamber 1 (S204). The wafer 3 transferred into the film forming chamber 1 is placed on the wafer stage 2 in the film forming chamber 1. Although not shown in FIG. 11, an Ir target 5 is placed on the target stage 4 in the film forming chamber 1 so as to face the wafer 3 placed on the wafer stage 2. Further, a shield 6 is provided in the film forming chamber 1.

  A film forming process for the wafer 3 is performed in the film forming chamber 1 (S205). After the film forming process for the wafer 3, the transfer robot 26 transfers the wafer 3 from the film forming chamber 1 to the load lock chamber 23 (S206). The wafer 3 transferred into the load lock chamber 23 is installed in the load lock chamber 23.

  The transfer robot 25 transfers the wafer 3 installed in the load lock chamber 23 to the wafer aligner 22 and sets it on the stage of the wafer aligner 22 (S207).

  When the detection sensor 27 detects that the wafer 3 is set on the stage of the wafer aligner 22, the detection sensor 27 sends a wafer detection detection signal to the reflectance measurement device and the resistance measurement device (S208).

  The reflectance measuring device that has received the wafer detection detection signal from the detection sensor 27 measures the reflectance of the IrOx film of the wafer 3 installed on the stage of the wafer aligner 22 (S209). For example, when the reflectance measuring apparatus receives a detection signal for wafer detection from the detection sensor 27, the reflectance measuring apparatus irradiates the IrOx film of the wafer 3 with light of a predetermined wavelength (for example, a wavelength of 480 nm), and reflects the light reflected thereby. Then, the reflectance of the IrOx film on the wafer 3 is measured.

  The resistance measuring device that has received the detection signal of the wafer detection from the detection sensor 27 measures the sheet resistance of the IrOx film of the wafer 3 installed on the stage of the wafer aligner 22 (S210). For example, the resistance measurement apparatus may measure the sheet resistance of the IrOx film of the wafer 3 installed on the stage of the wafer aligner 22 by a non-contact measurement method such as a four-probe method or an eddy current method. In addition, the resistance measuring apparatus may measure the sheet resistance of the IrOx film of the wafer 3 installed on the stage of the wafer aligner 22 using a probe.

  After measuring the reflectivity and sheet resistance of the IrOx film on the wafer 3, the transfer robot 25 transfers the wafer 3 installed on the stage of the wafer aligner 22 to the wafer carrier 21 and stores it in the wafer carrier 21 ( S211).

  As described in the processing of S201 and S202, the wafer 3 before film formation processing is taken out from the wafer carrier 21 by the transfer robot 25, and the wafer 3 is set on the stage of the wafer aligner 22. In this case, the control unit 13 may control the reflectance measuring device and the resistance measuring device so as not to perform the reflectance measurement and the sheet resistance measurement on the wafer 3 before the film forming process. .

  In the second embodiment, the example in which the wafer aligner 22 is provided with the reflectance measuring device and the resistance measuring device has been described. However, the wafer aligner 22 may be provided with either the reflectance measuring device or the resistance measuring device. Further, the measurement method of the reflectance and sheet resistance of the IrOx film of the wafer 3 described in the second embodiment is an example, and the reflectance and sheet resistance of the IrOx film of the wafer 3 are measured by other measurement methods. Is not excluded.

<Modification>
Further, the semiconductor manufacturing apparatus 10 according to the second embodiment may be modified as follows. A semiconductor manufacturing apparatus 10 according to this modification will be described with reference to FIG. FIG. 13 is a diagram showing an example of the structure of the semiconductor manufacturing apparatus 10 according to this modification. In the semiconductor manufacturing apparatus 10 according to this modification and the semiconductor manufacturing apparatus 10 according to the second embodiment, the detection sensor 31 is provided in the transfer chamber 24 and the reflectance measuring apparatus (not shown) is provided in the wafer aligner 22. The difference is that a reflectance measuring device (not shown) is provided in the transfer chamber 24. The detection sensor 31 is electrically connected to a control unit 13 (not shown). The control unit 13 receives a detection signal from the detection sensor 31.

  The transfer robot 26 transfers the wafer 3 after the film formation process from the film formation chamber 1 into the load lock chamber 23. As indicated by a thick arrow D in FIG. 13, the wafer 3 passes through the transfer chamber 24, and a detection sensor 31 is provided on a path through which the wafer 3 passes. The detection sensor 31 provided in the transfer chamber 24 detects whether or not the wafer 3 is present at a predetermined position in the transfer chamber 24 (a position immediately below the detection sensor 31 in FIG. 13).

  When the detection sensor 31 detects that the wafer 3 is present at a predetermined position in the transfer chamber 24, the detection sensor 31 sends a wafer detection detection signal to the reflectance measuring device. The reflectance measuring apparatus that has received the wafer detection detection signal from the detection sensor 31 measures the reflectance of the IrOx film of the wafer 3 existing at a predetermined position in the transfer chamber 24. Since the method for measuring the reflectance of the IrOx film on the wafer 3 is the same as the measuring method by the semiconductor manufacturing apparatus 10 according to the second embodiment, the description thereof is omitted.

Further, as indicated by a thick arrow E in FIG. 13, the wafer 3 passes through the transfer chamber 24 even before the wafer 3 is formed. In this case, the control unit 13 may be configured not to perform the reflectance measurement on the wafer 3 before the film forming process by controlling the reflectance measuring apparatus.

It is explanatory drawing in the case of forming an IrOx film | membrane on a wafer. It is the figure which showed the relationship between the amount of switching polarization, and the reflectance of an IrOx film | membrane. It is the figure which showed the relationship between leakage current and the reflectance of an IrOx film | membrane. Is a diagram illustrating a relationship between the sheet resistance of the O ₂ gas flow rate and IrOx film when forming the relationships and IrOx film and the reflectance of the O ₂ gas flow rate and IrOx film when forming the IrOx film. It is the figure which showed the relationship between the reflectance of an IrOx film | membrane, and a shield life. It is the figure which showed the relationship between the sheet resistance of an IrOx film | membrane, and a shield life. A shield life, is a diagram showing the relationship between the flow rate of O ₂ gas in the case of forming a IrOx film. It is the figure which showed an example of the structure of the semiconductor manufacturing apparatus 10 which concerns on 1st Embodiment. It is the figure which showed an example of the structure of the semiconductor manufacturing apparatus 10 which concerns on 1st Embodiment. 4 is a flowchart showing a flow of processing for changing the flow rate of O ₂ gas introduced into the film forming chamber 1. It is the figure which showed an example of the structure of the semiconductor manufacturing apparatus 10 which concerns on 2nd Embodiment. It is a flowchart which shows the flow of the process which measures the reflectance and sheet resistance of an IrOx film | membrane. It is the figure which showed an example of the structure of the semiconductor manufacturing apparatus 10 which concerns on the modification of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deposition chamber 2 Wafer stage 3 Wafer 4 Backing plate 5 Ir target 6 Shield 10 Semiconductor manufacturing device 11 O ₂ gas concentration meter 12, 16 Pipe 13 Control unit 14 O ₂ gas introduction device 15 Ar gas introduction device 21 Wafer carrier 22 Wafer Aligner 23 Load lock chamber 24 Transfer chamber 25, 26 Transfer robot 27, 31 Detection sensor

Claims (6)

A semiconductor manufacturing apparatus for manufacturing a semiconductor device having a ferroelectric capacitor composed of an upper electrode, a dielectric and a lower electrode,
An introduction part for introducing oxygen gas contained in a mixed gas for forming the upper electrode into the semiconductor wafer installed in the film forming chamber into the film forming chamber;
A controller for controlling the flow rate of oxygen gas introduced into the film forming chamber;
A measuring unit for measuring the concentration of oxygen gas contained in the mixed gas in the film forming chamber,
When the oxygen gas concentration value measured by the measurement unit is not within the predetermined value range, the control unit introduces the oxygen gas so that the oxygen gas concentration value falls within the predetermined value range. Semiconductor manufacturing equipment that changes the flow rate.   The semiconductor manufacturing apparatus according to claim 1, wherein the measuring unit measures a concentration of oxygen gas contained in the mixed gas existing around the semiconductor wafer.   2. The semiconductor manufacturing method according to claim 1, wherein the measurement unit measures a concentration of oxygen gas contained in the mixed gas existing around an inner wall surface of a shield provided in the film forming chamber so as to surround the semiconductor wafer. apparatus. A reflectance measuring unit for measuring the reflectance of the upper electrode formed on the semiconductor wafer,
When the reflectance value measured by the reflectance measurement unit is less than a predetermined value, the control unit changes the oxygen gas introduction flow rate so that the reflectance value of the upper electrode is equal to or greater than a predetermined value. The semiconductor manufacturing apparatus according to any one of claims 1 to 3. A resistance measuring unit that measures the sheet resistance of the upper electrode formed on the semiconductor wafer;
The said control part changes the introduction flow rate of the said oxygen gas so that the value of the said sheet resistance may become less than predetermined value, when the value of the sheet resistance measured by the said resistance measurement part is more than predetermined value. 5. The semiconductor manufacturing apparatus according to any one of items 1 to 4. A method of manufacturing a semiconductor device having a ferroelectric capacitor composed of an upper electrode, a dielectric and a lower electrode,
Introducing an oxygen gas contained in a mixed gas for forming the upper electrode into a semiconductor wafer placed in the film forming chamber into the film forming chamber;
A control step of controlling the flow rate of oxygen gas introduced into the film forming chamber;
A measurement step of measuring the concentration of oxygen gas contained in the mixed gas in the film forming chamber,
In the control step, when the oxygen gas concentration value measured in the measurement step is not within the predetermined value range, the oxygen gas introduction is performed so that the oxygen gas concentration value is within the predetermined value range. A method for manufacturing a semiconductor device, wherein the flow rate is changed.

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