JP2005118832A - Laser beam machining method and laser beam machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining method capable of smoothly removing a low-k film on streets formed on a semiconductor substrate and metallic patterns for testing partially disposed on the streets. <P>SOLUTION: The laser beam machining method for a semiconductor wafer 20 which is laminated with the low dielectric constant insulator film 213 on the surface of the semiconductor substrate 21, is formed with a plurality of circuits 121 by the streets 211 formed like a grid and is partially disposed with the metallic patterns 214 for testing on the streets includes a metallic pattern coordinate setting process of setting the coordinate values of the metallic patterns 214 for testing disposed on the streets 211 of the semiconductor wafer 20 and a laser beam machining process of removing the metallic patterns for testing and the low dielectric constant insulator film by irradiating the regions where the metallic patterns 214 for testing set by the metallic pattern coordinate setting process exist and the region of the low dielectric constant insulator film 213 with a laser beam under respectively different machining conditions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, a low dielectric constant insulating film is laminated on the surface, and a plurality of circuits are formed by streets formed in a lattice shape, and a test metal pattern is partially disposed on the streets. The present invention relates to a semiconductor wafer laser processing method and a laser processing apparatus.

  As is well known to those skilled in the art, in the semiconductor device manufacturing process, a plurality of regions are defined by streets (scheduled lines) arranged in a lattice pattern on the surface of a substantially disk-shaped semiconductor substrate. A semiconductor wafer in which a circuit such as an IC or an LSI is formed in a region is cut along the streets to divide each circuit into individual semiconductor chips. Cutting along the streets of a semiconductor wafer is usually performed by a cutting device called a dicer. This cutting apparatus has a chuck table for holding a semiconductor wafer as a workpiece, a cutting means for cutting the semiconductor wafer held on the chuck table, and a movement for relatively moving the chuck table and the cutting means. Means. The cutting means includes a rotating spindle rotated at a high speed and a cutting blade mounted on the spindle. The cutting blade is composed of a disk-shaped base and an annular cutting edge mounted on the outer peripheral portion of the side surface of the base. The cutting edge is fixed by electroforming diamond abrasive grains having a grain size of about 3 μm, for example, with a thickness of 20 μm. It is formed to the extent.

  In recent years, inorganic films such as SiOF and BSG (SiOB) on the surface of semiconductor substrates such as silicon wafers, polyimides, parylenes, etc. are used to improve the processing capability of circuits such as ICs and LSIs. A semiconductor wafer having a form in which a low dielectric constant insulator film (Low-k film) made of an organic film, which is a polymer film, is laminated has been put into practical use. However, the Low-k film is laminated in multiple layers (5 to 15 layers) like mica and is very fragile. Therefore, when cutting along the street with a cutting blade, the Low-k film peels off. There is a problem that the peeling reaches the circuit and causes fatal damage to the semiconductor chip.

  In order to solve the above-mentioned problem, the present applicant applies a laser beam to the low-k film formed on the street to remove the low-k film, and the street from which the low-k film has been removed is removed with a cutting blade. A machining apparatus for cutting was proposed as Japanese Patent Application No. 2002-131777.

  However, in a semiconductor wafer in which a test metal group called a test element group (Teg) for testing the function of a circuit is partially arranged on a low-k film on a street, the low-k film is provided with a low-k film. Even if the laser beam is irradiated for removal, there is a problem that the metal pattern made of copper, aluminum or the like prevents the laser beam and the Low-k film cannot be removed smoothly. Therefore, when the laser beam output is increased to such an extent that the metal pattern can be removed and the street is irradiated with the laser beam, the semiconductor substrate in the street portion where only the low-k film is formed is damaged and the debris is scattered, and this debris is a circuit. A new problem arises in that the quality of the semiconductor chip is deteriorated by adhering to a bonding pad connected to the semiconductor device.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is a low-k film on a street formed on a semiconductor substrate and a test metal pattern partially disposed on the street. It is providing the laser processing method and laser processing apparatus which can remove smoothly.

In order to solve the above main technical problem, according to the present invention, a low dielectric constant insulator film is laminated on the surface of a semiconductor substrate, and a plurality of circuits are formed by streets formed in a lattice shape. A semiconductor wafer laser processing method in which a test metal pattern is partially disposed,
A metal pattern coordinate value setting step for setting a coordinate value of the test metal pattern disposed on the street of the semiconductor wafer;
The region where the test metal pattern set by the metal pattern coordinate value setting step and the region of the low dielectric constant insulator coating are irradiated with laser beams under different processing conditions, respectively. A laser processing step of removing the dielectric insulator film,
A laser processing method is provided.

  In the metal pattern coordinate value setting step, the coordinate value of the test metal pattern is set based on the design drawing of the semiconductor wafer. The laser processing step includes a metal pattern removing step of removing the test metal pattern by irradiating the test metal pattern with a laser beam, and a low dielectric constant insulator by irradiating the region of the low dielectric constant insulator film with the laser beam. And a low dielectric constant insulator film removing step for removing the film.

In order to solve the main technical problem, according to the present invention, a plurality of circuits are formed by streets formed in a lattice pattern on the surface of a semiconductor substrate, and a test metal pattern is partially disposed on the streets. A laser processing apparatus for laser processing a semiconductor wafer being used along the street,
A chuck table for holding the semiconductor wafer, a laser beam irradiation means for irradiating the semiconductor wafer held on the chuck table with a laser beam, a processing feed means for relatively processing and feeding the chuck table and the laser beam irradiation means, Control means for controlling the laser beam irradiation means and the processing feeding means; and input means for inputting the coordinate values of the test metal pattern disposed on the street of the semiconductor wafer to the control means,
The control means includes storage means for storing the coordinate value of the test metal pattern input by the input means, and based on the coordinate value of the test metal pattern stored in the storage means, Controlling the laser beam irradiating means and the processing feeding means so as to irradiate a laser beam to an area where the test metal pattern is located
A laser processing apparatus is provided.

  According to the present invention, the low dielectric constant insulator film formed on the street of the semiconductor wafer and the test metal pattern are irradiated with laser beams under different processing conditions, so that the low dielectric constant can be obtained without damaging the semiconductor substrate or circuit. The rate insulator film and the metal pattern can be removed smoothly.

  Hereinafter, a laser processing method and a laser processing apparatus according to the present invention will be described in more detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a laser processing apparatus constructed according to the present invention. A laser processing apparatus shown in FIG. 1 includes a stationary base 2, a chuck table mechanism 3 that is disposed on the stationary base 2 so as to be movable in a machining feed direction indicated by an arrow X, and holds a workpiece. The laser beam irradiation unit support mechanism 4 is movably disposed in an index feed direction indicated by an arrow Y perpendicular to the direction indicated by the arrow X in FIG. 2, and the laser beam unit support mechanism 4 is movable in a direction indicated by an arrow Z. And an arranged laser beam irradiation unit 5.

  The chuck table mechanism 3 includes a pair of guide rails 31, 31 arranged in parallel along the machining feed direction indicated by the arrow X on the stationary base 2, and the arrow X on the guide rails 31, 31. A first slide block 32 movably disposed in the processing feed direction; and a second slide block 33 disposed on the first slide block 32 movably in the index feed direction indicated by an arrow Y; A support table 35 supported by a cylindrical member 34 on the second sliding block 33 and a chuck table 36 as a workpiece holding means are provided. The chuck table 36 includes a suction chuck 361 formed of a porous material, and holds, for example, a disk-shaped semiconductor wafer, which is a workpiece, on the suction chuck 361 by suction means (not shown). . Further, the chuck table 36 is rotated by a pulse motor (not shown) disposed in the cylindrical member 34.

  The first sliding block 32 is provided with a pair of guided grooves 321 and 321 fitted to the pair of guide rails 31 and 31 on the lower surface thereof, and in the index feed direction indicated by an arrow Y on the upper surface thereof. A pair of guide rails 322 and 322 formed parallel to each other are provided. The first sliding block 32 configured as described above is processed by the arrow X along the pair of guide rails 31, 31 when the guided grooves 321, 321 are fitted into the pair of guide rails 31, 31. It is configured to be movable in the feed direction. The chuck table mechanism 3 in the illustrated embodiment includes a machining feed means 37 for moving the first sliding block 32 along the pair of guide rails 31 and 31 in the machining feed direction indicated by the arrow X. The processing feed means 37 includes a male screw rod 371 disposed in parallel between the pair of guide rails 31 and 31, and a drive source such as a pulse motor 372 for rotationally driving the male screw rod 371. One end of the male screw rod 371 is rotatably supported by a bearing block 373 fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 372 by transmission. The male screw rod 371 is screwed into a penetrating female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the first sliding block 32. Therefore, when the male screw rod 371 is driven to rotate forward and backward by the pulse motor 372, the first sliding block 32 is moved along the guide rails 31, 31 in the machining feed direction indicated by the arrow X.

  The second sliding block 33 is provided with a pair of guided grooves 331 and 331 which are fitted to a pair of guide rails 322 and 322 provided on the upper surface of the first sliding block 32 on the lower surface thereof. By fitting the guided grooves 331 and 331 to the pair of guide rails 322 and 322, the guided grooves 331 and 331 are configured to be movable in the indexing and feeding direction indicated by the arrow Y. The chuck table mechanism 3 in the illustrated embodiment is for moving the second slide block 33 along the pair of guide rails 322 and 322 provided in the first slide block 32 in the index feed direction indicated by the arrow Y. First index feeding means 38 is provided. The first index feed means 38 includes a male screw rod 381 disposed in parallel between the pair of guide rails 322 and 322, and a drive source such as a pulse motor 382 for rotationally driving the male screw rod 381. It is out. One end of the male screw rod 381 is rotatably supported by a bearing block 383 fixed to the upper surface of the first sliding block 32, and the other end is connected to the output shaft of the pulse motor 382. The male screw rod 381 is screwed into a penetrating female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the second sliding block 33. Therefore, when the male screw rod 381 is driven to rotate forward and reversely by the pulse motor 382, the second slide block 33 is moved along the guide rails 322 and 322 in the index feed direction indicated by the arrow Y.

  The laser beam irradiation unit support mechanism 4 includes a pair of guide rails 41, 41 arranged in parallel along the indexing feed direction indicated by the arrow Y on the stationary base 2, and the arrow Y on the guide rails 41, 41. The movable support base 42 is provided so as to be movable in the direction indicated by. The movable support base 42 includes a movement support portion 421 that is movably disposed on the guide rails 41, 41, and a mounting portion 422 that is attached to the movement support portion 421. The mounting portion 422 is provided with a pair of guide rails 423 and 423 extending in the direction indicated by the arrow Z on one side surface in parallel. The laser beam irradiation unit support mechanism 4 in the illustrated embodiment includes a second index feed means 43 for moving the movable support base 42 along the pair of guide rails 41, 41 in the index feed direction indicated by the arrow Y. doing. The second index feed means 43 includes a male screw rod 431 disposed in parallel between the pair of guide rails 41, 41, and a drive source such as a pulse motor 432 for rotationally driving the male screw rod 431. It is out. One end of the male screw rod 431 is rotatably supported by a bearing block (not shown) fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 432. The male screw rod 431 is screwed into a female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the moving support portion 421 constituting the movable support base 42. For this reason, when the male screw rod 431 is driven to rotate forward and backward by the pulse motor 432, the movable support base 42 is moved along the guide rails 41, 41 in the index feed direction indicated by the arrow Y.

  The laser beam irradiation unit 5 in the illustrated embodiment includes a unit holder 51 and laser beam irradiation means 52 attached to the unit holder 51. The unit holder 51 is provided with a pair of guided grooves 511 and 511 that are slidably fitted to a pair of guide rails 423 and 423 provided in the mounting portion 422. By being fitted to the guide rails 423 and 423, the guide rails 423 and 423 are supported so as to be movable in the direction indicated by the arrow Z.

  The illustrated laser beam application means 52 includes a cylindrical casing 521 that is fixed to the unit holder 51 and extends substantially horizontally. In the casing 521, as shown in FIG. 2, a pulse laser beam oscillation means 522 and a transmission optical system 523 are arranged. The pulse laser beam oscillation means 522 is composed of a pulse laser beam oscillator 522a composed of a YAG laser oscillator or a YVO4 laser oscillator, and a repetition frequency setting means 522b attached thereto. The transmission optical system 523 includes an appropriate optical element such as a beam splitter. A condenser 524 containing a condenser lens (not shown) composed of a combination lens that may be in a known form is attached to the tip of the casing 521.

  The laser beam oscillated from the pulse laser beam oscillating means 522 reaches the condenser 524 through the transmission optical system 523, and a predetermined focused spot diameter is applied to the workpiece held on the chuck table 36 from the condenser 524. Irradiated with D. As shown in FIG. 3, when the pulse laser beam having a Gaussian distribution is irradiated through the objective lens 524a of the condenser 524, the condensed spot diameter D is D (μm) = 4 × λ × f / (π × W ), Where λ is defined by the wavelength (μm) of the pulse laser beam, W is the diameter (mm) of the pulse laser beam incident on the objective lens 524a, and f is the focal length (mm) of the objective lens 524a.

  Returning to FIG. 1, the description will be continued. At the front end portion of the casing 521 constituting the laser beam irradiation means 52, an alignment means 6 for detecting a processing region to be laser processed by the laser beam irradiation means 52 is disposed. . The alignment unit 6 includes an illuminating unit that illuminates the workpiece, an optical system that captures an area illuminated by the illuminating unit, an imaging device (CCD) that captures an image captured by the optical system, and the like. The captured image signal is sent to the control means described later.

  The laser beam irradiation unit 5 in the illustrated embodiment includes a condensing point position adjusting means 53 for moving the unit holder 51 along the pair of guide rails 423 and 423 in the direction indicated by the arrow Z. The condensing point position adjusting means 53 includes a male screw rod (not shown) disposed between the pair of guide rails 423 and 423, and a drive source such as a pulse motor 532 for rotationally driving the male screw rod. Thus, the unit holder 51 and the laser beam irradiation means 52 are moved along the guide rails 423 and 423 in the direction indicated by the arrow Z by driving the male screw rod (not shown) in the forward and reverse directions by the pulse motor 532. In the illustrated embodiment, the laser beam irradiation means 52 is moved upward by driving the pulse motor 532 forward, and the laser beam irradiation means 52 is moved downward by driving the pulse motor 532 in reverse. It has become. Therefore, the condensing point position adjusting means 53 can adjust the condensing point position of the laser beam irradiated by the condenser 524 attached to the tip of the casing 521.

  The laser processing apparatus in the illustrated embodiment includes a control means 10 and an input means 11. The control means 10 is constituted by a microcomputer, and a central processing unit (CPU) 101 that performs arithmetic processing according to a control program, a read-only memory (ROM) 102 that stores a control program, etc., and a read / write that stores arithmetic results and the like A random access memory (RAM) 103, an input interface 104, and an output interface 105. As will be described later, the input means 11 inputs the coordinate values of the test metal pattern disposed on the street of the semiconductor wafer to the control means 10. Data relating to the coordinate value of the test metal pattern input to the control means 10 by the input means 11 is stored in a random access memory (RAM) 103. Accordingly, the random access memory (RAM) 103 functions as a storage unit that stores the coordinate values of the test metal pattern by the input unit 11. In addition, a detection signal from the imaging unit 6 or the like is input to the input interface 104 of the control unit 10. A control signal is output from the output interface 105 of the control means 10 to the pulse motor 372, pulse motor 382, pulse motor 432, pulse motor 532, laser beam irradiation means 52, and the like.

Next, a laser processing method for processing a semiconductor wafer using the laser processing apparatus described above will be described.
FIG. 4A shows the semiconductor wafer 20 processed by the laser processing apparatus together with the coordinates in a state where the chuck table 36 is held at a predetermined position, and FIG. 4B shows the semiconductor wafer. A state in which 20 is rotated 90 degrees from the state of FIG. FIG. 5 is an enlarged cross-sectional view of the semiconductor wafer 20 shown in FIG. The semiconductor wafer 20 shown in FIGS. 4 and 5 is divided into a plurality of regions by a plurality of streets (planned cutting lines) 211 arranged in a lattice pattern on the surface 21a of the semiconductor substrate 21 made of a silicon wafer. A circuit 212 such as an IC or an LSI is formed in the region. The semiconductor wafer 20 is formed by laminating a low dielectric constant insulator film 213 on the surface of the semiconductor substrate 21, and a test element group (Teg) for testing the function of the circuit 212 is provided on the street 211. A plurality of test metal patterns 214 to be referred to are partially arranged.

  When laser processing the above-described semiconductor wafer 20 along the street 211, the coordinate value of the test metal pattern 214 disposed on the street 211 is input from the input means 11 to the control means 10 (metal pattern coordinate value setting step). ). The coordinate values of the test metal pattern 214 correspond to the coordinate value map (A) shown in FIG. 6A corresponding to the state shown in FIG. 4A and the state shown in FIG. The coordinate value map (B) shown in FIG. The data regarding the coordinate value maps (A) and (B) can be created based on the design drawing of the semiconductor wafer 20. Data regarding the coordinate value maps (A) and (B) input from the input unit 11 to the control unit 10 in this way is stored in a random access memory (RAM) 103.

  As described above, the semiconductor wafer 20 in which the data relating to the coordinate values of the test metal pattern 214 arranged on the street 211 is input to the control means 10 is the chuck constituting the chuck table mechanism 3 of the laser processing apparatus shown in FIG. It is conveyed onto the suction chuck 361 of the table 36 with the surface 20a facing upward, and is sucked and held by the suction chuck 361. The chuck table 36 that sucks and holds the semiconductor wafer 20 in this way is moved along the guide rails 31 and 31 by the operation of the processing feed means 37 and is positioned immediately below the imaging means 6 disposed in the laser beam irradiation unit 5. It is done.

  When the chuck table 36 is positioned immediately below the image pickup means 6, the alignment means 6 and the control means 10 execute an alignment operation for detecting a processing region to be laser processed on the semiconductor wafer 20. That is, the alignment unit 6 and the control unit 10 irradiate the laser beam along the street 211 formed in a predetermined direction of the semiconductor wafer 20 (the X coordinate direction in the state shown in FIG. 3A) and the street 211. Image processing such as pattern matching for performing alignment with the condenser 524 of the laser beam irradiation unit 5 is performed, and alignment of the laser beam irradiation position is performed. Similarly, the laser beam is applied to the street 211 formed in the direction extending perpendicularly to the predetermined direction formed in the semiconductor wafer 20 (the X coordinate direction in the state shown in FIG. 3B). Irradiation position alignment is performed.

  As described above, when the street 211 formed on the semiconductor wafer 20 held on the chuck table 36 is detected and the alignment of the laser beam irradiation position is performed, the chuck table 36 is moved to move to FIG. As shown in (a), one end (the left end in the figure) of the predetermined street 211 on which the test metal pattern 214 is disposed is positioned directly below the condenser 524 of the laser beam irradiation means 52. Then, the chuck table 36 is moved at a predetermined processing feed speed in the processing feed direction indicated by the arrow X1. When the chuck table 36 moves in the machining feed direction indicated by the arrow X1 in this way, the test is performed based on the data relating to the coordinate values of the test metal pattern 214 disposed on the street 211 shown in FIG. When the X coordinate value at which the metal pattern 214 is located is reached, the control means 10 outputs a control signal to the laser beam irradiation means 52, and the test metal pattern 214 is irradiated with the laser beam from the condenser 524. 214 is removed. Then, as shown in FIG. 7B, while the other end (right end in the figure) of the predetermined street 211 reaches a position directly below the condenser 524 of the laser beam irradiation means 52, a plurality of streets 211 are arranged. Only the test metal pattern 214 is removed (metal pattern removal step).

The metal pattern removal process described above is set to the following processing conditions in the illustrated embodiment. The thickness of the test metal pattern 214 is set to 5 μm.
Processing conditions: Metal pattern removal process Light source: YAG laser or YVO4 laser Wavelength: 355 nm (ultraviolet light)
Output: 1.0W
Repeat frequency: 50 kHz
Pulse width: 10 ns
Condensing spot diameter: φ25μm
Processing feed rate: 50 mm / sec

  When the metal pattern for test 214 arranged on the street 211 is removed by executing the metal pattern removing process as described above, the metal pattern 214 is removed as shown in FIG. The other end (the right end in the figure) of the predetermined street 211 is positioned directly below the condenser 524 of the laser beam irradiation means 52. Then, the control means 100 outputs a control signal to the laser beam irradiation means 52 and irradiates the chuck table 36 with a laser beam from the condenser 524 to the low dielectric constant insulating film 213 while performing a predetermined process in the process feed direction indicated by the arrow X2. Move at feed rate. As a result, as shown in FIG. 8B, the low dielectric constant insulator film 213 formed on the street 211 is removed while moving to one end (left end in the figure) of the predetermined street 211 (low dielectric constant). Rate insulator coating removal step).

The above-described low dielectric constant insulator film removing step is set to the following processing conditions in the illustrated embodiment. The thickness of the low dielectric constant insulator coating 203 is set to 10 μm.
Processing conditions: Low dielectric constant insulator coating removal process Light source: YAG laser or YVO4 laser Wavelength: 355 nm (ultraviolet light)
Output: 0.5W
Repeat frequency: 50 kHz
Pulse width: 10 ns
Condensing spot diameter: φ25μm
Processing feed rate: 100 mm / sec

  As described above, when the street detection process, the metal pattern removal process, and the low dielectric constant insulator film removal process are executed along the predetermined street 211, the chuck table 36, and thus the semiconductor wafer 20 held by the chuck table 36, and the semiconductor wafer 20 held by the chuck table 36 are Indexing and feeding is performed in the indexing and feeding direction shown by the interval of the streets 211 (indexing process), and the metal pattern removing process and the low dielectric constant insulator film removing process are performed. When the metal pattern removal process and the low dielectric constant insulator film removal process are performed on all the streets 211 extending in a predetermined direction in this way, the chuck table 36 and, therefore, the semiconductor wafer 20 held by the chuck table 36 are moved to 90. The metal pattern removing step and the low dielectric along each street 211 formed in a direction (X coordinate direction in the state shown in FIG. 4B) extending at right angles to the predetermined direction. By executing the dielectric insulator film removal step, the test metal pattern 214 and the low dielectric constant insulator film 213 formed on all the streets 211 of the semiconductor wafer 20 are removed.

  In the above-described embodiment, an example in which the output of the laser beam to be irradiated and the processing feed rate are changed as the processing conditions of the test metal pattern removal step and the low dielectric constant insulator coating removal step has been shown. You may make it change only.

  If the metal pattern 214 and the low dielectric constant insulator film 213 formed on all the streets 211 of the semiconductor wafer 20 are removed as described above, the chuck table 36 holding the semiconductor wafer 20 is Then, the semiconductor wafer 20 is returned to the position where the semiconductor wafer 20 is sucked and held. Here, the sucking and holding of the semiconductor wafer 20 is released. Then, the semiconductor wafer 20 is transferred to the dicing process by a transfer means (not shown). In this dicing process, the semiconductor wafer 20 is cut along the streets 211 by a cutting device having a cutting blade, and is divided into individual semiconductor chips. At this time, since the test metal pattern 214 and the low dielectric constant insulating film 213 formed on the street 211 are removed, the peeling that occurs when the low dielectric constant insulating film is cut by the blade is prevented in advance. can do.

  In each of the above-described embodiments, an example in which the metal pattern removing process and the low dielectric constant insulator film removing process are performed separately is shown. However, when processing one street 211, the low dielectric constant is illustrated. By irradiating a laser beam by alternately changing the processing conditions of the region where only the insulating film 213 is formed and the processing conditions of the region where the low dielectric constant insulating film 213 and the test metal pattern 214 are disposed The metal pattern removing step and the low dielectric constant insulator film removing step can be executed by one processing feed.

The perspective view of the laser processing apparatus comprised according to this invention. The block diagram which shows simply the structure of the laser beam processing means with which the laser processing apparatus shown in FIG. 1 is equipped. FIG. 3 is a simplified diagram for explaining a focused spot diameter of a laser beam irradiated from the laser beam processing unit shown in FIG. 2. FIG. 2 is an explanatory diagram showing a relationship between the semiconductor wafer to be processed by the laser processing method according to the present invention and coordinates in a state where the semiconductor wafer is held at a predetermined position of the chuck table of the laser processing apparatus shown in FIG. 1. FIG. 5 is an enlarged sectional view of the semiconductor wafer shown in FIG. 4. The coordinate value map of the metal pattern for a test arrange | positioned on the street of the semiconductor wafer shown in FIG. Explanatory drawing of the metal pattern removal process in the laser processing method by this invention. Explanatory drawing of the low dielectric constant insulator film removal process in the laser processing method by this invention.

Explanation of symbols

2: stationary base 3: chuck table mechanism 31: guide rail 36: chuck table 4: laser beam irradiation unit support mechanism 41: guide rail 42: movable support base 5: laser beam irradiation unit 51: unit holder 52: laser beam processing means 522 : Laser beam oscillation means 523: Laser beam modulation means 524: Condenser 6: Alignment means Imaging means 10: Control means 20: Semiconductor wafer 21: Semiconductor substrate 211: Street 212: Circuit 213: Low dielectric constant insulator coating 214: For test Metal pattern

Claims (4)

A semiconductor in which a low dielectric constant insulator film is laminated on the surface of a semiconductor substrate and a plurality of circuits are formed by streets formed in a lattice shape, and a test metal pattern is partially disposed on the streets Wafer laser processing method,
A metal pattern coordinate value setting step for setting a coordinate value of the test metal pattern disposed on the street of the semiconductor wafer;
The region where the test metal pattern set by the metal pattern coordinate value setting step and the region of the low dielectric constant insulator coating are irradiated with laser beams under different processing conditions, respectively. A laser processing step of removing the dielectric insulator film,
A laser processing method characterized by the above.   The laser processing method according to claim 1, wherein in the metal pattern coordinate value setting step, the coordinate value of the test metal pattern is set based on a design drawing of the semiconductor wafer.   The laser processing step includes a metal pattern removing step of irradiating the test metal pattern with a laser beam to remove the test metal pattern, and irradiating the region of the low dielectric constant insulator coating with a laser beam to provide the low dielectric constant. The laser processing method of Claim 1 including the low dielectric constant insulator film removal process of removing an insulator film. A laser for laser processing a semiconductor wafer, in which a plurality of circuits are formed by streets formed in a lattice shape on the surface of a semiconductor substrate, and a test metal pattern is partially disposed on the streets along the streets A processing device,
A chuck table for holding the semiconductor wafer, a laser beam irradiation means for irradiating the semiconductor wafer held on the chuck table with a laser beam, a processing feed means for relatively processing and feeding the chuck table and the laser beam irradiation means, Control means for controlling the laser beam irradiation means and the processing feeding means; and input means for inputting the coordinate values of the test metal pattern disposed on the street of the semiconductor wafer to the control means,
The control means includes storage means for storing the coordinate value of the test metal pattern input by the input means, and based on the coordinate value of the test metal pattern stored in the storage means, Controlling the laser beam irradiating means and the processing feeding means so as to irradiate a laser beam to an area where the test metal pattern is located
Laser processing equipment characterized by that.

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