JP2002217132A - Vacuum deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum deposition apparatus, for example, in which a evaporated material is deposited on a wafer surface with its semiconductor wafer, i.e., a work to be deposited, being rotated around an evaporation source, as well as, a step coverage is fine and a recessed part is eliminated, and a yield is improved even if there is a step-like part on the wafer surface. SOLUTION: A metal thin film is formed by depositing the evaporation material from the evaporation source on the wafer surface having the step part of the semiconductor wafer 7 which is attached on a dome revolving an rotating for the evaporation source in a chamber 1 drawn almost in vacuum. The semiconductor wafer 7 is rotativebly attached on the dome 3, and the vacuum deposition apparatus A is equipped with a rotation-driving means for rotating the semiconductor wafer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a metal electrode wiring of a semiconductor by, for example, depositing a deposition material on a wafer surface while rotating a semiconductor wafer as a workpiece to be deposited around a deposition source. The present invention relates to a vacuum evaporation apparatus used.

[0002]

2. Description of the Related Art Conventionally, as a vacuum evaporation apparatus, as shown in FIG. 5, a chamber 1 in which an internal space is reduced to a predetermined pressure by a vacuum apparatus, and an evaporation material (an evaporation source) are placed. Hearth 2, a disk-shaped dome 3 mounted on a concave portion via an adsorption device or the like so as to direct a plurality of semiconductor wafers 7 toward the evaporation source and revolve, and a dome supporting the dome 3 A shaft 4, a planet arm 5 that rotatably supports the dome shaft 4 and revolves facing the vapor deposition source;
And a rotary motor 6 that rotates from the upper part of the chamber 1 through the rotary motor.

When the dome 3 rotates, a rotating wheel 4a provided at an end of the dome shaft 4 comes into contact with an upper surface of a planet rail 1a provided over the entire periphery of a side wall surface of the chamber 1.
With the revolution of the planet arm 5, the rotating wheel 4a rolls,
It rotates around the axis of the dome shaft 4.

[0004] The semiconductor wafer 7 is
The revolving motion is performed by the revolution by the planet arm 5 and the revolution by the dome 3, so that the thickness of the deposited metal thin film is uniform.

[0005]

However, as shown in FIG. 6, a semiconductor wafer 7 arranged opposite to a vapor deposition source is provided.
Is gradually revolved from the upper position (wafer A) to the lower position (wafer D) with respect to the deposition source by the rotation of the dome 3, the angle θ of the deposition trajectory d with respect to the central axis c of the deposition source increases. As shown in FIG. 7, the distribution of the deposition density is θ
, The thickness tends to decrease from dense to sparse, so that the thickness of the film formed by vapor deposition increases in the upper position and decreases in the lower position. The inclination of the vapor deposition surface of the semiconductor wafer 7 with respect to the vapor deposition trajectory d is small at the upper position, and large at the lower position.

Therefore, when there is a step on the vapor deposition surface of the semiconductor wafer 7 due to the etched interlayer insulating film, a wafer A, for example, of the plurality of semiconductor wafers 7 mounted on the dome 3 is taken as an example. The formation of the metal thin film at the step 10 will be described.

As shown in FIG. 8A, first, when the wafer A is at the uppermost position, the metal thin film (deposition) 9 deposited on the surface of the interlayer insulating film 8 has a substantially uniform thickness. ,
Since the evaporation density of the emitted evaporation material is also high, the film thickness is formed relatively thick. On the other hand, in the step portion 10 between the interlayer insulating films 8 and 8, since the inclination of the evaporation surface with respect to the evaporation locus d is small, the range occupied by the projected portion 10a is small. The metal thin film 9 is formed with a substantially uniform film thickness on the projected portion.

However, when the wafer A is rotated by 180 degrees due to the rotation of the dome 3 accompanying the rotation of the planet arm 5, as shown in FIG.
The projecting portion is switched by reversing the vertical position between the edge and the end b, and the vapor deposition density decreases, and the inclination of the wafer surface with respect to the vapor deposition trajectory d increases. Therefore, the thickness of the metal thin film 9a deposited on the deposition surface is reduced as a whole, and the area occupied by the projected portion 10a in the step portion 10 is increased.

As a result, even if the metal thin film 9a is deposited and formed on the portion of the step portion 10 where the metal thin film 9 is not laminated at the upper position of the previous stage, the thickness of the metal thin film 9a is small. The entire part cannot be sufficiently covered so that the film thickness becomes uniform. That is, the step coverage of the deposited metal thin film is inferior. Further, since the area occupied by the projected portion 10a is large, it is roughly divided into a portion where the metal thin films 9 and 9a are stacked and a portion where the metal thin film 9a is not stacked.

[0010] Thereafter, by further rotating the dome 3, FIG.
As shown in FIG. 8, when the wafer A is rotated by 180 degrees (returns to the position shown in FIG. 8A), at the position shown in FIG. The portion where the thin film 9a is not laminated) escapes from the projected portion and moves to the non-projected portion, whereupon the metal thin film 9 is deposited and the metal thin films 9 and 9 are laminated.

On the other hand, at the position shown in FIG. 8B, the portion where the metal thin film 9a is laminated (the portion other than the projected portion, hereinafter referred to as the non-projected portion) is projected at the position shown in FIG. Parts and non-projected parts.

The metal thin film 9 is vapor-deposited on the non-projected portion and the metal thin films 9, 9a, 9 are laminated to increase the film thickness. In the projected portion 10a, the metal thin film 9a is formed. Thus, the metal thin film 9 is not newly deposited and the film thickness remains thin, and as shown in FIG. 10, a narrow portion 9c of the film thickness occurs.

As described above, if the semiconductor wafer 7 is simply rotated by the planet arm 5 and the dome 3 with respect to the vapor deposition source by the large arm and the small dome 3, as shown in FIG.
In this case, a constricted portion 9c in which the thickness of the metal thin film 9 becomes non-uniform is generated. As a result, the yield of semiconductor wafers deteriorates, leading to a decrease in reliability. The vacuum evaporation apparatus according to the present invention is proposed to solve such a problem.

[0014]

The gist of the present invention for solving the above-mentioned problems is that a semiconductor mounted on a dome that revolves and rotates with respect to a deposition source in a vacuum chamber. In a vacuum deposition apparatus for forming a metal thin film by depositing a deposition material from the deposition source on a wafer surface having a step portion of a wafer, the semiconductor wafer is rotatably mounted on the dome and the semiconductor wafer is rotated. That is, a rotation drive unit is provided. The rotation driving means is constituted by a drive motor provided on the dome and a belt or a chain for transmitting the rotation drive of the motor, or is constituted by a planetary gear mechanism revolving with respect to a planet arm for revolving the dome. That is to say.

According to the vacuum evaporation apparatus of the present invention, the semiconductor wafer rotatably mounted on the dome is largely revolved by the planet arm, revolved by the dome, and further rotated by the rotation driving means. In addition, at the step portion on the wafer surface (vapor deposition surface) where the metal thin film is formed, the residence time before entering the projection portion and exiting from the projection portion is shortened. Therefore, even if the vertical position of the semiconductor wafer revolved by the dome changes, the effect of staying in the projected portion and preventing the deposition material from being deposited is reduced.

Therefore, the semiconductor wafer mounted on the dome is revolved by the dome while relieving the influence of the projected portion of the step by rotating, thereby reducing the variation in the vapor deposition density distribution of the vapor deposition material. The metal thin film to be deposited on the portion is formed with a substantially uniform film thickness, and the step coverage of the step is improved.

[0017]

Next, a vacuum deposition apparatus according to the present invention will be described with reference to the drawings. In order to facilitate understanding of the invention, portions corresponding to those of the conventional example will be described with the same reference numerals as in the conventional example.

As shown in FIG. 1, a vacuum evaporation apparatus A includes a hearth 2 for placing an evaporation material (an evaporation source) in a chamber 1 whose internal space is reduced to a predetermined pressure by the vacuum apparatus.
A disk-shaped dome 3 mounted on the concave surface portion 3a via the suction device 16 so as to direct a plurality of semiconductor wafers 7 toward the vapor deposition source and revolve, and a dome shaft 4 supporting the dome 3, A planet arm 5 that rotatably supports the dome shaft 4 and revolves opposite the vapor deposition source.
A shaft 6a for rotating the planet arm 5; and a rotary motor 6 having a motor shaft connected to the shaft 6a in the upper part of the chamber 1.

In the dome 3, a rotating wheel 4 a provided on the dome shaft 4 comes into contact with a planetary rail 1 a laid in a ring shape on the side wall surface of the chamber 1 over the entire circumference, and rolls with the revolving motion of the planet arm 5. By rotating while moving, the rotating wheel 4a and the dome shaft 4 are integrally rotated (rotated).

The rotation of the dome 3 causes a plurality of (for example, 12) semiconductor wafers 7 to revolve with respect to the evaporation source. Further, as shown in FIG. 2, the dome 3 is provided with a rotary drive unit for a semiconductor wafer, for example, as shown in FIG.
One drive motor 11 is provided on the back surface of the dome for two semiconductor wafers 7 as one set.
A belt or a chain 12 is stretched over one pulley 11a and a pulley 7b provided on a shaft 7a of the semiconductor wafer 7, respectively. Drive motor 1 electrically connected
By one rotation, the two semiconductor wafers 7 rotate with respect to the dome 3. The drive motor 11 and transmission means 12 such as a belt or a chain are similarly provided on the other semiconductor wafers 7.

The rotation driving means for rotating the semiconductor wafer 7 with respect to the dome 3 is not limited to the above-described embodiment. For example, as shown in FIG.
A bevel gear 13 that is fixed inside the planet arm 5 and does not rotate is provided around the center axis, and a bevel gear 14 that meshes with the bevel gear 13 is provided on the shaft 7a to form a planetary gear mechanism.

In this case, the bevel gear 13 serves as a sun gear, the bevel gear 14 serves as a planetary gear, and the dome 13 serves as an operating arm. The shaft 7 that rotates integrally with the bevel gear 14
a, a pulley 7c is provided on a shaft 7a of another semiconductor wafer 7, and the pulleys 7c, 7d
Transmission means 15 such as a belt or a chain is installed between them.

In this mechanism, by rotating the planet arm 5, the semiconductor wafer 7 revolves around the sun gear 13 and becomes integral with the planetary gear 14 which rotates, and the dome 3
, Whereby the other semiconductor wafer 7 is driven and rotated by the transmission means 15 such as a belt. Although the above two examples have been described as the rotation driving means, the present invention is not limited to this, and any mechanism capable of rotating the semiconductor wafer 7 with respect to the dome 3 by known mechanism means may be used.

In order to form a metal electrode wiring by depositing a vapor deposition material on the wafer surface using the vacuum vapor deposition apparatus A of the present invention configured as described above, a required number of semiconductor wafers 7 are attached to each dome 3 by a suction apparatus. 16 and the like, and the interior space of the chamber 1 is set to a predetermined pressure by a vacuum device to make it substantially in a vacuum state. Then, the rotary motor 6 is driven, and when the mechanism shown in FIG. Then, the drive motor 11 is driven. Then, the evaporation material is emitted from the hearth 2.

When the planet arm 5 is rotated via the shaft 6a by the rotation of the rotary motor 6, the semiconductor wafer 7 revolves largely around the axis 6b, and the rotating wheels roll on the upper surface of the planet rail 1a. When the dome 3 rotates together with the rotation of 4a, the dome 3 revolves slightly around the axis 4b, and also rotates together with the suction device 16 by the rotation of the drive motor 11.

Due to the rotation of the semiconductor wafer 7, the residence time of the stepped portion 10a on the wafer surface between the projected portion 10a of the vapor deposition material and the projected portion 10a with respect to the deposition locus d is reduced, and the stepped portion 10a is not in contact with the projected portion 10a. The metal thin film in the projected portion is formed under substantially the same conditions, and the film thickness becomes substantially uniform. Also, chamber 1
The influence on the step coverage due to the variation of the deposition density in the inside is also mitigated by the rotation of the semiconductor wafer 7.

In this manner, as shown in FIG. 4, the step coverage at the step portion 10 on the wafer surface is improved, and the metal thin film 9 having a uniform film thickness as a whole is formed. This eliminates the risk of disconnection.

[0028]

As described above, in the vacuum deposition apparatus according to the present invention, the stepped portion of the semiconductor wafer attached to the dome that rotates and rotates with respect to the deposition source in the vacuum chamber. In a vacuum deposition apparatus for forming a metal thin film by depositing a deposition material from the deposition source on the wafer surface having a, the semiconductor wafer is rotatably mounted on the dome, and a rotation driving means for rotating the semiconductor wafer is provided. Since the semiconductor wafer is revolved by the dome, the semiconductor wafer also revolves, and the residence time before entering and projecting from the projecting portion of the step on the wafer surface is short, and the effect is weakened, and the step coverage of the metal thin film is reduced. Is improved. Therefore, while improving the yield of semiconductor wafers,
This has an excellent effect of improving the reliability of quality.

[0029] The rotation driving means is constituted by a driving motor provided on the dome and a belt or a chain for transmitting the rotation of the motor, or a planetary gear mechanism revolving with respect to a planet arm for revolving the dome. Therefore, the semiconductor wafer can be revolved and rotated.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of a vacuum evaporation apparatus according to the present invention.

FIG. 2 is an enlarged explanatory view showing a configuration of a driving rotation means provided on a dome in the vacuum evaporation apparatus according to the present invention.

FIG. 3 is an enlarged explanatory view showing another configuration of the drive rotating means provided on the dome in the vacuum evaporation apparatus according to the present invention.

FIG. 4 is an enlarged explanatory view showing a film formation state of a metal thin film formed on a step portion of a semiconductor wafer by the vacuum evaporation apparatus according to the present invention.

FIG. 5A is a front view showing a schematic configuration of a vacuum evaporation apparatus according to a conventional example, and FIG.

FIG. 6 is an explanatory view showing that the vapor deposition density differs depending on the vertical position of the semiconductor wafer in the vacuum vapor deposition apparatus according to the conventional example.

FIG. 7 is an explanatory diagram showing a relationship between a distance from a deposition source and a deposition density.

FIG. 8 is a diagram illustrating a state of vapor deposition at a step portion of a semiconductor wafer in a vacuum vapor deposition apparatus according to the conventional example, in which an explanatory diagram (A) when the semiconductor wafer is at an upper position and an explanatory diagram ( B).

FIG. 9 shows a state of vapor deposition at a step portion of the semiconductor wafer in the vacuum vapor deposition apparatus according to the conventional example, in which the semiconductor wafer moves from the upper position to the lower position, revolves to the upper position, and returns to the original position. FIG.

FIG. 10 is an explanatory view showing a state in which a narrow portion is formed in the step portion in the metal thin film in the semiconductor wafer having the step portion.

[Explanation of symbols]

1 chamber, 1a planetar, 2 hearths, 3
Dome, 4 rotating shafts, 4a rotating wheels, 4b shaft center,
5 planet arm, 6 rotating motor, 6a axis, 7 semiconductor wafer, 7a axis, 7b, 7c, 7d pulley,
8 interlayer insulating film, 9 metal thin film, 10 step, 10a
Projection part, 11 Drive motor, 11a Pulley, 12
Belt, 13 bevel gear (sun gear), 14 bevel gear (planetary gear), 15 belt, 16 suction device, A Vacuum vapor deposition device of the present invention.

Claims (2)

[Claims] In a vacuum chamber, a vapor deposition material is vapor-deposited from the vapor deposition source on a wafer surface having a step portion of a semiconductor wafer which is revolved with respect to the vapor deposition source and attached to a dome which rotates. A vacuum evaporation apparatus for forming a metal thin film by using the method described above, wherein the semiconductor wafer is rotatably attached to the dome, and rotation driving means for rotating the semiconductor wafer is provided. 2. The rotation driving means comprises a driving motor provided on the dome and a belt or a chain for transmitting the rotation of the motor, or a planetary gear revolving around a planet arm for revolving the dome. The vacuum evaporation apparatus according to claim 1, wherein the vacuum evaporation apparatus is configured by a mechanism.