JP2006066446A - Method of manufacturing semiconductor device, and semiconductor manufacturing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device manufacturing method and semiconductor manufacturing equipment that can surely protect the surface of a chip and can evenly remove a crushed layer, formed after separation into chips. <P>SOLUTION: The semiconductor device manufacturing method comprises processes of forming an element region and an electrode on a semiconductor substrate, forming a protective film on the electrode, pasting a sheet on the protective film, dividing the semiconductor substrate into individual chips, and extending the sheet under controlled prescribed conditions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device manufacturing method and a semiconductor manufacturing apparatus, which are improved chip separation methods for semiconductor devices such as optical semiconductor devices formed on a wafer, for example.

  In general, when a chip is separated by dicing in a manufacturing process of a semiconductor device such as an LED, a crushed layer is formed on an end face. By removing this by etching, deterioration of characteristics such as luminance can be suppressed ( For example, see Patent Document 1).

For example, as shown in FIG. 14, the surface of the chip 116 on the n-side electrode 106a side is covered and protected with a resist 105, the p-side electrode 106b side is attached to an adhesive sheet 107, separated for each chip, and then wet etched. Thus, the crushed layer can be removed.
JP-A-6-326352

  However, it is actually difficult to wet-etch the crushed layer uniformly, and there is a problem that the crushed layer remains even after wet etching and the characteristics deteriorate.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor device manufacturing method and a semiconductor manufacturing apparatus capable of removing the conventional problems, reliably protecting the chip surface, and uniformly removing the crushed layer after chip separation. It is what.

  According to one aspect of the present invention, a step of forming an element region and an electrode on a semiconductor substrate, a step of forming a protective film on the electrode, a step of attaching a sheet on the protective film, and the semiconductor substrate There is provided a method for manufacturing a semiconductor device, comprising a step of separating each chip and a step of stretching the sheet under controlled predetermined conditions.

  Moreover, according to one aspect of the present invention, the sheet fixing means for fixing the peripheral portion of the sheet in which a plurality of semiconductor chips separated for each chip are attached to the central portion, and the central portion of the sheet are fixed. There is provided a semiconductor manufacturing apparatus comprising: a position changing unit that changes a relative position of the sheet with respect to a fixed position of a peripheral portion; and a control unit that controls the position changing unit.

According to one embodiment of the present invention, it is possible to reliably protect the chip surface and uniformly remove the crushed layer after chip separation in the manufacturing process of the semiconductor device.

Embodiments of the present invention will be described below with reference to the drawings.

1 to 10 and 12 show the manufacturing process of the semiconductor device of this embodiment. First, as shown in FIG. 1, a light emitting layer forming portion 2 made of, for example, an InGaAlP-based or AlGaAs-based compound semiconductor is formed on a first semiconductor substrate 1 made of, for example, n-type GaAs. At this time, for example, the n-type cladding layer 2a made of an InGaAlP-based compound semiconductor, having a carrier concentration of about 1.0 × E17 to 1.0 × E19 cm ⁻³ and a thickness of about 0.1 to 2.0 μm, The active layer 2b is made of an InGaAlP-based compound semiconductor that is non-doped and has a band gap energy smaller than that of the cladding layer, and has a thickness of about 0.1 to 2.0 μm, and is doped with Zn to have a carrier concentration of 1.0 × E16. A semiconductor layer including a p-type cladding layer 2c made of an InGaAlP-based compound semiconductor having the same composition as the n-type cladding layer 2 and having a thickness of about .about.1.0.times.E19 cm.sup.- ³ and a thickness of about 0.1 to 2.0 .mu.m was laminated. A structure can be used.

Such a light emitting layer formation part 2 is formed as follows, for example. First, an n-type GaAs substrate 1 is placed in, for example, an MOCVD (metal organic chemical vapor deposition) apparatus, and reactive gases such as trimethylgallium (hereinafter referred to as TMG), trimethylaluminum (hereinafter referred to as TMA), trimethylindium (hereinafter referred to as “TMA”). TMIn) and phosphine (hereinafter referred to as PH ₃ ) are introduced together with n-type dopant gas SiH ₄ and carrier gas hydrogen (H ₂ ), epitaxially grown at about 500 to 900 ° C., and carrier concentration of 1.0 × An n-type clad layer 2a made of In _0.49 (Ga _0.3 Al _0.7 ) _0.51 P having a size of about E16 to 1.0 × E19 cm ^{−3 is} formed to a thickness of about 0.5 μm.

Next, the TMA of the reaction gas is decreased to increase the TMG, the dopant gas is stopped, and the active layer 2b made of, for example, non-doped In _0.49 (Ga _0.75 Al _0.3 ) _0.51 P is about 0.5 μm, similar to the n-type cladding layer 2 For example, In _0.49 (Ga _0.3 Al _0.7 ) _{0.51 in} which the dopant gas is p-type dimethylzinc (DMZ) and the carrier concentration is p-type and the carrier concentration is about 1.0 × E17 to 1.0 × E19 cm ^−3. The p-type cladding layer 2c made of P is epitaxially grown by about 0.5 μm.

On the other hand, as shown in FIG. 2, a GaP buffer layer 4 is formed on the second semiconductor substrate 3 made of, for example, GaP by MOCVD. At this time, for example, using the MOCVD method, the reaction gases TMG, TMZn, and PH ₃ are introduced together with the carrier gas hydrogen (H ₂ ), epitaxially grown at about 500 to 900 ° C., and formed on the p-type GaP substrate 3. A Zn-doped GaP buffer layer 4 is grown to a thickness of about 0.1 to 5.0 μm.

Next, as shown in FIG. 3, the surface of the GaP buffer layer 4 and the surface of the light emitting layer forming part 2 previously laminated on the n-type GaAs substrate are bonded. At this time, for example, the adhesive surfaces are overlapped and heated to about 700 ° C. while being pressed with a pressure of about 0.1 to 10 kg / cm ² , for example.

Then, as shown in FIG. 4, wet etching is performed with a mixed solution of H ₂ O ₂ and H ₂ SO ₄ for a processing time of 10 to 60 minutes to remove the GaAs substrate.

In this way, as shown in FIG. 5, a structure in which the GaP buffer layer 4 and the light emitting layer forming portion 2 are sequentially laminated on the GaP semiconductor substrate 3 is obtained.

Next, as shown in FIG. 6, dicing lines are formed on the surface of the light emitting layer forming portion 2 by a dicing method. At this time, patterning is performed with a predetermined resist 5, and half dicing is first performed to a width of 40 to 50 μm and a depth of the GaP layer of 10 to 20 μm. Thereafter, as shown in FIG. 7, wet etching is performed with a mixed solution of HCl: H ₂ O ₂ : H ₂ O = 95: 2: 3 for a treatment time of 10 to 30 minutes, and the crush layer on the end face is removed. Further, the resist is stripped with a resist stripping solution.

  Further, as shown in FIG. 8, an n-side electrode 6a is formed on the surface of the light emitting layer forming portion by depositing Au-Ti alloy or Au-Zn-Ni alloy by vacuum deposition or the like and patterning. To do. Further, an Au—Ge—Ni alloy or the like is provided on the entire surface of the GaP substrate to form the p-side electrode 6b. Then, resist 5 ', 5 "is applied to protect the p and n side electrodes during processing.

Then, as shown in FIG. 9, the n-side electrode surface is fixed with an adhesive sheet 7 . As this pressure-sensitive adhesive sheet, for example, a sheet obtained by applying a pressure-sensitive adhesive material (bori) 7b of about 30 μm onto a vinyl chloride sheet substrate 7a having a thickness of 50 to 100 μm is used. Thereafter, as shown in FIG. 10, the surface of the GaP substrate 3 is diced straight to form a rectangular parallelepiped shape, and then the adhesive sheet 7 is stretched.

At this time, the adhesive sheet is stretched by a stretching apparatus as shown in FIG. 11, for example. In this stretching apparatus, a stage 12 installed in the frame 11 is connected to a cylinder 14 via a shaft 13. Further, a variable position stopper 15 for adjusting the stroke width is provided at a predetermined position of the shaft 13, and a speed control control mechanism (not shown) for moving the stage 12 up and down is connected to the cylinder 14. , The ascending speed is controlled. The adhesive sheet 7 to which the diced chip 16 is bonded is sandwiched between two rings 17a and 17b and fixed to the frame 11 above the stage. A temperature control mechanism including a plurality of thermocouples 18 is provided in the periphery, and the temperature at the time of stretching is controlled.

With such a stretching device, for example, the adhesive sheet 7 is stretched as follows. First, the adhesive sheet 7 around the diced chip 16 diced to the first ring 17a is attached, and the adhesive sheet 7 is sandwiched between the second rings 17b, thereby fixing the adhesive sheet 7 to the rings 17a and 17b. . Further, after these rings 17a and 17b are fixed to the frame 11, they are held at a controlled temperature for a predetermined time. Next, as shown in FIG. 12, the cylinder 14 is controlled, and the stage 12 on which the Teflon (registered trademark) ring 19 is placed is moved up to a predetermined speed and stroke. Since the end of the adhesive sheet 7 is fixed by the rings 17a and 17b, the entire adhesive sheet 7 is uniformly stretched as the stage 12 is raised. Then, the O-ring 20 is fitted to the outside of the Teflon (registered trademark) ring 19 and fixed in a state where the adhesive sheet is stretched, and then the peripheral adhesive sheet is cut.

At this time, as a condition for stretching the adhesive sheet,
(1) Stretching speed
(2) Stretch amount
(3) Temperature during stretching
(4) The holding time before stretching is controlled. For example, when a pressure-sensitive adhesive sheet having a substrate thickness of 80 to 120 μm and an initial adhesive strength of the adhesive material (paste) of 0.1 to 2.0 N is used with a vinyl chloride sheet substrate,
(1) The stretching speed is suitably 1.0 to 3.0 cm / sec. This is because if the speed is too slow, appropriate productivity cannot be obtained, while if it is too fast, the adhesive (slipping) is torn off.

  (2) The stretching amount is suitably 200 to 300 μm. This is because if the amount of stretching is small, the etching solution cannot be sufficiently penetrated into the end surface of the chip. On the other hand, if the amount is too large, the adhesive (slipping) is torn off.

  (3) The temperature during stretching is suitably 50 to 150 ° C. This is because if the pressure is too low, the adhesive material (slave) cannot be sufficiently softened, while if it is too high, the element may be deteriorated.

  (4) The holding time before stretching is suitably 10 to 90 seconds. This is because if the adhesive is too short, the adhesive material (slave) cannot be sufficiently softened, whereas if it is too long, appropriate productivity cannot be obtained.

  These conditions are appropriately set depending on the pressure-sensitive adhesive sheet to be used, and are not limited to these conditions.

  In this way, by controlling the stretching condition to a predetermined condition, the tensile strength of the adhesive material (slave) is controlled, and resist peeling due to the stretching of the adhesive material (slave) when the adhesive sheet is stretched can be suppressed.

In this way, the adhesive sheet is stretched to increase the distance between the chips to, for example, 500 μm or more, and then the crushed layer is etched using an etching solution such as (HCl + H ₂ O ₂ + H ₂ O). At this time, since the etching liquid can smoothly penetrate into the chip end surface by stretching the adhesive tape, the crushed layer can be etched uniformly. In addition, since resist peeling is suppressed, the occurrence of electrode squeeze (a state in which an electrode that should originally be protected by the resist is etched) is suppressed during etching for removing the crushed layer.

Then, in order to further improve the optical characteristics, an unevenness having a height of about 1.0 μm and a period of 0.5 to 1.0 μm is formed on the side surface of the GaP substrate 3 by, for example, HF frost treatment, and then shown in FIG. In this way, the resist 5 ″ on the surface of the p-side electrode 6b is stripped with a stripping solution. Furthermore, the adhesive sheet 7 to the p-side electrode 6b faces 'paste, peeled adhesive sheet 7 is adhered to the n-side electrode 6a surface, the resist 5 of the n-side electrode 6a faces' and to release treatment with a release liquid A LED chip is formed.

  In the present embodiment, an InGaAlP compound semiconductor is used as the light emitting layer forming portion, but the same applies to the case where an AlGaAs compound semiconductor is used. In addition, a double heterojunction in which the active layer is sandwiched between both clad layers, the active layer and both clad layers are made of different materials, for example, a mixed crystal ratio of Al, and carriers are confined in the active layer to make the active layer a light-emitting layer. Although a structure is used, a structure in which a pn junction is formed without an active layer and a light emitting layer is formed at the pn junction may be used. Furthermore, specific compositions, thicknesses, and carrier concentrations are given as the semiconductor layers constituting the semiconductor light emitting element, but the invention is not limited to these examples, and various semiconductor layers can be used. Moreover, although the rectangular shape was used for the chip shape, the end face may have a taper in order to improve the light extraction efficiency. Further, in addition to the optical semiconductor, the present invention can be applied to a semiconductor device that removes the fractured layer by etching.

  Moreover, in the pressure-sensitive adhesive sheet stretching process, specific conditions and methods are listed in the preceding and following processes, but the process is not limited to this. For example, the sheet ends may be held at a plurality of points (for example, 8 points) at equal intervals and stretched in the horizontal direction (outer peripheral direction). Also, the method for controlling each condition is not particularly limited.

  In addition, this invention is not limited to embodiment mentioned above. Various other modifications can be made without departing from the scope of the invention.

4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. The figure which shows the adhesive sheet extending apparatus in 1 aspect of this invention. The figure which shows the adhesive sheet extending apparatus in 1 aspect of this invention. 4A and 4B illustrate a manufacturing process of a semiconductor device according to one embodiment of the present invention. The figure which shows the manufacturing process of the conventional semiconductor device.

Explanation of symbols

1 GaAs substrate
2 light emitting layer forming portion 3 GaP substrate 4 GaP buffer layer 5, 5 ′, 5 ″ resist 6, 106 electrode
7 , 107 Adhesive sheet 11 Frame 12 Stage 13 Shaft 14 Cylinder 15 Stopper 16, 116 Dicing tip 17 Ring 18 Thermocouple 19 Teflon (registered trademark) ring 20 O-ring

Claims (5)

Forming an element region and an electrode on a semiconductor substrate;
Forming a protective film on the electrode;
Attaching a sheet on the protective film;
Separating the semiconductor substrate for each chip;
A method of manufacturing a semiconductor device, comprising a step of stretching the sheet under controlled predetermined conditions.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the predetermined condition includes at least one of stretching speed, stretching amount, temperature at stretching, and holding time before stretching.   The method of manufacturing a semiconductor device according to claim 1, further comprising a step of removing a crushed layer formed on the substrate after the stretching step. A sheet fixing means for fixing a peripheral portion of a sheet in which a plurality of semiconductor chips separated for each chip are attached to the central portion;
Position changing means for changing a relative position between a center portion of the sheet and a fixed position of a peripheral portion of the fixed sheet;
A semiconductor manufacturing apparatus comprising control means for controlling the position changing means.   The semiconductor manufacturing apparatus according to claim 4, further comprising temperature control means for controlling temperature.

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