JPH029535A - Method and device of manufacturing thin base sheet - Google Patents

Abstract

PURPOSE:To simplify a manufacturing process by a method wherein, in a manufacture of a thin base sheet, e.g. crystal, silicon, the end surface of an ingot is ground in a flat manner and the end surface side is cut to a thin piece with a given thickness, and the thin piece is mounted to a chuck to grind a cut surface. CONSTITUTION:The end surface of an ingot 22 supported by a support means 20 is ground through rotation of a grinding stone 43 by moving slide 3 and a moving table 7, and is then cut to a thin piece 25 by means of a blade 13 of a thin base sheet cutting means 10. A thin base sheet 25 is adsorbed by a vacuum chuck 56, and in turn is adsorbed by a vacuum chuck 59 of a rotary disc 57 to release the thin base plate from attraction of the chuck 56, and the thin base sheet 25 is turned over by rotating the rotary disc 57 in a 180 deg. arc. Thereafter, the thin base sheet is adsorbed by a vacuum chuck 35 of a support member 33 to render attraction of the chuck 59 ineffective, and the cut surface of the thin base sheet 25 is ground through rotation of a grinding stone 43. The above motion is repeated through orderly movement of the slide 3 and the moving table 7, the thin base sheet 25 is formed, in order, and is contained in a cassette 60 for carry-out. This constitution simplifies a manufacturing process and enables improvement of quality.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method and a multi-tasking machine for manufacturing thin substrates of crystal, silicon, gallium arsenide, etc. The present invention relates to a method and apparatus for manufacturing a thin substrate in which both sides of the substrate are ground.

[Prior Art J] Conventionally, as a method for manufacturing thin substrates, such as wafers, by cutting ingots of ink or silicone into thin pieces, 1 usually involves the steps (main steps) shown in Figure 7. A method has been adopted.

That is, an ingot is cut thinly in a wafer cutting step 701, and the periphery of the cut wafer is chamfered in a beveling step 702 to prevent chipping, scratches, cracks, etc. during lapping.
Next, in a double-sided wrapping step 703, the wafer/
Both sides of the wafer are lapped to remove warpage generated during +JJ disconnection, crack layers and saw marks on the wafer surface, and the wafer is processed to have a predetermined thickness.

Thereafter, in a polishing step 704, both sides of the wafer are polished to remove warpage and improve smoothness, and then an etching step 70 is performed.
In step 5, a machining process is performed to remove the altered layer on the wafer surface caused by the AM machining process. Finally, in mirror polishing step 06, the surface of the wafer is polished again for finishing, thereby producing a final wafer.

In the manufacture of such wafers, three major problems are the removal of warpage that occurs during processing of the wafer, particularly when cutting the wafer. So, wafer! Although various i'J cutting methods have been proposed, it has been difficult to perform cutting while significantly reducing the occurrence of warpage in any of the methods. For this reason.

It is necessary to reliably remove warpage in the processing step after cutting the wafer, but conventional wafer manufacturing methods have not been able to sufficiently remove warpage.

In conventional wafer manufacturing methods, it is thought that the reason why warpage generated during wafer cutting cannot be sufficiently removed is as follows.

In other words, when cutting a wafer in the wafer cutting process,
Warpage occurs in the wafer 81 (Fig. '58 (a)) due to changes in cutting resistance due to the incision during cutting and deformation of the blade (seat M, ) caused by heat generation, etc. (Fig. '58 (a)). Therefore, in the lapping process and polishing process, The wafer 81 is processed while applying pressure at a constant fi of 85.86 on the upper and lower sides to remove warpage (FIG. 8(b)).

However, in this case, the wafer 81 is a thin piece and generally has a concave shape on one side and a convex shape on the other side, and is curved as a whole, so pressure is applied from above and below at a constant rate of 185.86. Due to the elasticity of the wafer 81, the wafer 81 is bent into a flat shape.

For this reason, large warps that bend and do not become flat even when pressurized at a constant fi of 85.86 can be removed by lapping and polishing, but warps that bend due to elastic deformation and become flat when pressurized can be removed by lapping and polishing. The sled could not be removed. Therefore, when the vertical pressure due to the constant g185.86 was removed, the wafer returned to its warped shape (FIG. 8(C)), and it was impossible to remove more than a predetermined amount of warpage.

Therefore, as a method for manufacturing an iIj substrate that solves the above problems, Japanese Patent Application Laid-Open No. 61-106207 and Japanese Patent Application Laid-Open No. 62-2
As disclosed in No. 24537, etc., a manufacturing process was developed whose main manufacturing step 1 is shown in FIG.

That is, in this manufacturing method, in an end face grinding step 601, the end face of the ingot is ground to make a flat reference surface, and then in a wafer cutting step 602, the end face side of the ingot is cut into thin pieces of a predetermined thickness to form wafers. Next, the peripheral edge is chamfered in a beveling step 603, and then a one-side lapping step 604 is performed. Polishing step 605
Wafers are manufactured through 4 at 608°C.

Note that the lapping process 604 and the polishing process 605.1308 are intended to remove warpage and saw marks on the wafer as in the conventional manufacturing method.

[One problem to be solved] However, when one end surface of a wafer is processed by end-face grinding and the other surface is processed by single-sided lapping, the processing contents for both surfaces are different.

The altered layer produced by these machining processes has different aspects on both surfaces. It is difficult to completely remove a degraded layer in such a non-uniform state even if etching is performed as it is.

Therefore, if there is a large difference between the processing strain in end-face grinding and the processing strain in single-sided lapping, warpage may still remain on the wafer even after the double-sided polishing process or the double-sided lapping process. For that purpose, the 6th
In the conventional manufacturing method shown in the figure, it is usually necessary to insert a double-sided polishing process or a double-sided roughing process before the etching process to make the deteriorated layers formed on both surfaces of the wafer uniform, which reduces the work time. There was a problem with spending a lot of money.

The present invention was made in order to solve the problems mentioned above, and it not only simplifies the manufacturing process and shortens the manufacturing time, but also enables the manufacturing of thin substrates (wafers) with even higher precision and higher quality. The purpose of the present invention is to provide a thin substrate manufacturing method and an apparatus thereof.

[Means for Solving the Problems]-h 1] In order to achieve the objective 1, the thin substrate manufacturing method of the present invention includes grinding the end face of the ingot and the cut face of the thin piece.
The end face of the ingot is ground flat, then the end face side of the ingot is cut into thin pieces of a predetermined thickness, and the cut thin pieces are then inverted and attached to a chuck parallel to the cut surface, and the νJ cross section of the thin pieces is ground. I'm used to it.

Further, in the invention of the thin substrate manufacturing apparatus, there is provided a thin substrate cutting means comprising a cylindrical blade mounting frame that can rotate freely once, a blade fixed to the blade mounting frame, and a thin substrate cutting means that fixes the ingot and cuts at least the above-mentioned An ingot support means movable in the radial direction of the blade and a thin substrate cut out from the ingot by the thin substrate cutting means are inverted and fixed with the cut surface facing up, and at least the same ingot support means as the above ingot support means are used. a thin substrate support means movable on a path; a thin substrate transfer means for inverting and transporting the thin substrate cut from the ingot by the thin substrate cutting means to the thin substrate support means; J provided opposite to the movement path of the substrate support means
: The ingot supporting means is fixed to the ingot support means, and the thin substrate supporting means is fixed to the top surface of the ingot.

[Example] An example of the present invention will be explained below with reference to the drawings.

First, a first embodiment of the thin substrate manufacturing apparatus of the present invention will be described with reference to FIGS. 1 to 3. 1 is a plan view of the thin substrate manufacturing apparatus, FIG. 2 is a front view thereof, and FIG. 3 is an enlarged view taken along the line A--A in FIG. 1.

51 and 2, 1 is a base, 10 is a thin substrate cutting means, 20 is an ingot supporting means, 30 is a thin substrate supporting means, 40 is a grinding means, and 50 is a thin substrate transporting means.

The blade mounting frame 12 is rotatably supported by a bearing ring 11 mounted on a base 1 and by hydrostatic bearings provided on the inner surface and both end surfaces of the bearing ring 11. The blade mounting frame 12 is formed into a cylindrical shape, and its front part (the ingot support means 20
a disc-shaped blade 1 having a diamond cutting wheel for cutting a thin substrate from an ingot on the side opposite to the ingot;
3, and the rear part is open. Further, a timing pulley 14 is provided on the rear outer periphery of the blade mounting frame 12 so that the rotational force of the motor 15 is transmitted via a transmission member such as a belt 16.

A guide rail 2 is provided laterally extending at the rear (upper part in FIG. 1) of the base l, and the feed table 3 can be moved on this guide rail 2. That is, the base l
A drive pulley 9 fixed to the motor 4 at one end and a tension pulley 5 at the other end are provided along the guide rail 2, and a timing belt is wound between the drive pulley 9 and the tension pulley 5. 6, the driving force of the motor 4 is transmitted to the feed table 3 to move it in the lateral direction.

Here, the feed table 3 is supported by the guide rail 2 by a hydrostatic bearing. Further, the feed table 3L is provided with a moving table 7. The moving table 7 is moved by the driving force of the motor 8 in the forward and backward direction of the base l on the feed table 3.

The ingot support means 20 and the thin substrate support means 30 are
They are provided at one end and the other end of the moving tapes 1 and 7, respectively, and are configured to move together with the movement of the moving table 7 in the front-back direction and the movement of the feed table 3 in the lateral direction.

The ingot support means 20 includes an index slide portion 21
have. This indexing slide aX section 21 has an ingot 22 a on its upper surface, and uses a driving force from a motor 23 to move the ingot 22 in the front-rear direction, that is, in the axial direction of the blade mounting frame 12, to remove a predetermined thickness from the ingot 22. It is designed to provide indexing feed for cutting thin substrates. Here, the ingot 22 is placed so that its axis is approximately at the same height as the center of the blade 13.
121 and fixed by a clamp member 24.

The thin substrate support means 30 is provided parallel to the ingot support means 20 on a movable table 7, and as shown in FIG. On the other hand, a support member 33 is rotatably attached via a support shaft 32. In addition, a tilt 3I adjuster 34 made of a piezoelectric element or the like is provided on a part of the opposing surfaces of the fixing base 31 and the support member 33, and this allows the support member 33 to rotate slightly. The mounting angle can be adjusted. moreover.

A vacuum chuck 35 for suctioning a thin substrate is formed on the front end surface of the support member 33 shown in E.

The grinding means 40 is provided on either side of the thin substrate cutting means 10 at a position facing the movement path of the ingot supporting means 20 and the thin substrate supporting means 30.

This grinding means 40 is equipped with a tool that is rotationally driven by a motor 41! ! 142, and a grindstone 43 is mounted on the end face of this tool mounting board 42.

The thin substrate transfer means 50 is composed of a first transfer means 51 and a second transfer means 52. The first transfer means 51 is 1. l! A moving rail 53 is provided at the front of the table 1 in parallel with the moving path of the thin substrate support means 30, and a sliding member 54 moves on this moving rail 53. The sliding member 54 includes an arm 55 that reciprocates in the axial direction of the blade mounting frame 12, that is, in the front-rear direction of the base 1. At the tip of the arm 55, a vacuum chuck 56 for suctioning a thin substrate is attached. is formed.

The first transfer means 51 adsorbs a thin piece of the ingot 22 cut within the blade attachment frame 12, that is, the thin substrate 25, moves in the lateral direction, and transfers it to the next second transfer means 52.

The second transfer means 52 is installed outside the blade attachment frame 12 between the path along which the support member 33 of the thin substrate support means 30 moves and the lateral movement end of the m-movement member 54 . The second transfer f stage 52 has a one-turn disk 57t-i, and this rotation tE.
A vacuum chuck 59 is formed on the end face of the zero-rotation plate 57, which is capable of reversing the thin substrate by rotating t57 by 180 degrees around the rotation axis 58a, and this vacuum chuck 59 attracts the thin substrate. Then, it is transferred from the first transfer means 51 to the support member 33 of the thin substrate support means 30. Also 1
Rotation I! 157 is approximately 90 degrees centering on the rotation axis 58b.
``It is designed to rotate.

In the drawing, 60 is a cassette for carrying out thin substrates, and 61 is an arm for carrying out thin substrates that have been ground. The W extraction arm 61 rotates approximately 180 degrees around a single rotation axis 62, and is adapted to attract a thin substrate by means of a vacuum chuck 63 provided at its tip. One rotational end of this unloading arm 61 faces the position where the rotation 11157 of the second transfer means 52 has rotated around the rotation shaft 58b. Further, the other rotating end is positioned directly above the cassette 60 for carrying out thin substrates.

64 is a displacement sensor, and 1. '
The probe 66 is positioned along the support rail 65 that has arrived at i1.
It is designed to move downward. The support rail 65 supports the grinding wheel 4
It extends parallel to the grinding surface of No.3. And probe 6
6 measures at least two upper and lower positions on the thin substrate adsorption surface of the vacuum chuck 35 of the thin substrate support means 30 and/or the surface of the thin substrate after grinding adsorbed to the vacuum chuck 35, and measures the detection signal. It is output to a processing device M (not shown). The zero constant processing device adjusts the inclination WJ straightener 34 of the support member 33 so that the relative displacement at the at least two detection positions is zero (that is, the difference in thickness of the thin substrate after grinding is zero). do. As a result, the vacuum chuck 35 of the support member 33 always moves parallel to the grindstone 43.

67 is a rotary dresser that rotates at high speed around a rotating shaft 68 provided on the side wall of the support member 33. A grinding wheel is used for this rotary dresser 67, and the grinding means 4
dressing the grindstone 43.

Next, an embodiment of the thin substrate manufacturing method of the present invention using the above-mentioned apparatus will be described.

First, the feed table 3 is moved in the direction of arrow a in the figure, and the movable table 7 is moved in the front and back direction fi8, and the grinding wheel 4 is
The end face of the ingot 22 is placed on the side of 3. moreover,
With a predetermined amount of grinding set by fine-tuning movement of the moving table 7 in the front-rear direction, the grindstone 43 is rotated, and the feed table 3 is gradually moved in the direction of the arrow a in the figure to grind the end face of the ingot 22. Grind.

Next, move the feed table 3 in the opposite direction to release the ingot 2.
2 to substantially coincide with the center of the blade 13. In this position, the moving table 7 is moved in the direction of the thin substrate cutting means 10 so that the end face of the ingot 22 is cut into the blade 13.
The center hole should be approximately the same as the center hole. Further, the index slide placement section 21 is moved in the same direction by -steps,
The ingot 22 is scaled so that the end surface of the ingot 22 enters into the blade attachment frame 12 slightly more than the center hole of the blade 13.

Next, while rotating the blade mounting frame 12.

The feed table 3 is gradually moved in the direction of the arrow a shown in the figure, and the ingot 22 is cut by the inner cutter of the blade 13. Note that a holding material 22a such as carbon is adhered to the side surface of the ingot 22 that is cut last, thereby preventing chipping from occurring on the side surface of the ingot 22.

At this time, the sliding member 54 of the first transfer means 51 is in a position facing the inner surface of the blade 13, and the arm 55 extends in the direction of the blade 13, and simultaneously cuts the ingot 22. The thin substrate 25 is sucked by a vacuum chuck 56. Thereafter, the arm 55 is moved backward and housed in the sliding member 54, and in this state, the sliding member 54 moves in the direction indicated by the arrow in the figure. At the end of the movement, the rotating disk 57 is in a position close to and facing the thin substrate 25 held at the tip of the arm 55 (vacuum chuck 56).
Simultaneously with the suction by the vacuum chuck 59 , the vacuum chuck 56 of the arm 55 releases suction and transfers the thin substrate to the rotary disk 57 .

%)) Rotation N157 with the S plate held by suction is rotated by rotating shaft 5.
The thin substrate 25 is turned over by rotating 180' around 8a.

Rotation I rotated 180'! 157, the Itj end face (vacuum chuck 35) of the support member 33 is placed in advance by lateral movement of the feed table 3 and movement of the moving table 7 in the front-rear direction. Simultaneously with the suction by the chuck 35, the vacuum chuck 59 of the rotary disk 57 releases the suction and transfers the thin substrate to the support member 33.The thin substrate thus transferred is suctioned to the support member 33 with the cut surface facing up. It will be retained.

In addition, before handing over the thin substrate, the displacement sensor 64 mentioned earlier is
by. Measurement of the relative position of the surface of the vacuum chuck 35 of the support member 33 and adjustment using the inclination y4 adjuster 34,
This is to maintain parallelism between the vacuum chuck 35 of the support member 33 and the grindstone 43.

Next, the movable table 7 is moved in the front-back direction to adjust the amount of grinding of the 181 substrate on the support member 33.
Then, the feed table 3 is gradually moved in the direction of the arrow a shown in the figure, and the grindstone 43 is rotated to grind the cut surface of the thin substrate.

The feeding during this grinding is carried out in the same direction by the movement of the feed table 3, similar to when the end face of the ingot 22 is ground, so that the grinding directions for both surfaces of the thin substrate are the same.

After finishing the grinding, the support member 33 is again connected to the rotary disk 57.
The rotating spirit 57, which has received the thin substrate, moves to the opposite position a and transfers the thin substrate to the rotating connection 57.
8a and 58b. At the same time, the unloading arm 61 rotates! The thin substrate is transferred to the vacuum chuck 63 at the tip of the carry-out arm 61 at a position opposite to the cassette 60.Then, the carry-out arm 61 rotates to transfer the thin substrate to a position directly above the carry-out cassette 60, and the thin substrate is transferred to the vacuum chuck 63 at the tip of the carry-out arm 61. 6
3, the thin substrate is quietly stored in the carrying-out cassette 60.

In this way, the thin substrate (
The wafers) are sequentially transported to the next process, and as shown in FIG. Etching 402. Mirror polishing 403': J processing is performed.

According to this method of manufacturing thin substrates, since both sides of the thin substrate are processed continuously using the same grindstone, not only is there no difference due to the grain size of the grindstone, but also both sides are processed with approximately equal cutting edges. can be processed. Moreover, since both sides of the thin substrate are ground by setting the grinding direction, grinding speed, etc. to the same conditions, the deteriorated layers produced by machining on both sides of the FK substrate can be made uniform, and the 4 deteriorated layers can be uniformly removed during the double-sided polishing process. Since it is possible to omit the manufacturing process for manufacturing, it is possible to simplify the manufacturing process and shorten the manufacturing process. Furthermore, it goes without saying that the thin substrate manufactured in this manner is free of molten metal, has high precision, and is of high quality.

FIG. 5 is a front view showing a second embodiment of the thin substrate manufacturing apparatus of the present invention. It should be noted that the same or corresponding parts as shown in FIG.

In this embodiment, the grinding means 40 is integrated into the blade mounting frame 12 to shorten the amount of acid transferred to the feed table 3, thereby realizing downsizing of the apparatus. That is, the grindstone 43 is provided on the outer periphery of the front end of the blade mounting frame 12.
The rotation of the grinding wheel 43 rotates the grinding wheel 43 to perform the grinding process.

According to this thin substrate manufacturing apparatus, first, the end of the ingot 22 is ground by the grindstone 43, and then the thin substrate is cut out from the ingot 22 by the plate 13. The thin substrate is transferred to the front end of the support member 33 (vacuum chuck 35). Then, the support member 33 is moved toward the blade mounting frame 12, and the cut end surface of the thin substrate is ground by the grindstone 43. In fact, by carrying out the same unloading operation as in the first embodiment shown above and going through the necessary post-processes, the fb)A M
The manufacturing process can be realized.

Isn't the month of unissued January limited to the example mentioned above? <,
Various modifications can be made without departing from the above principles.

For example, if Pj) & the plate cutting means and the second grinding means are
In addition to grinding and cutting the end face simultaneously, the process of grinding the thin substrate that has already been cut and mounted on the thin plate support means with the cut surface facing up is also accomplished by moving the feed table in the lateral direction. It is also possible to do both at the same time. In this case, if the grinding wheel for grinding the end of the ingot and the grinding wheel for grinding the thin substrate attached to the thin plate support means are made of the same material and are ground at the same rotation speed, and the grinding wheels are dressed at the same time, Since the other grinding conditions are the same, almost uniform machining is achieved, and products with the same high precision and quality can be obtained, and since machining on both sides is performed at the same time, it is possible to reduce the machining time by about half.

Furthermore, the terms "grinding" and "cutting" used in the above explanation are not limited to grinding or cutting using a normal dry or wet diamond grinding wheel, but also include grinding using other hard abrasive grains, electrolytic grinding, a-sonic grinding, Is it possible to adopt grinding methods such as vibration grinding? It is clear that it is 1.

Furthermore, it is also possible to employ wire electrical discharge machining as a thin substrate cutting means. In this case, the thin substrate in the embodiment of FIG. /J The cutting means is a device for wire cutting and a liquid tank, and when the ingot is moved to the position of the grinding means, the feed table moves downward to cross the line of the liquid tank. is also required.

The thin substrate to be manufactured by the present invention is a microcircuit or an I
It includes not only the wafer/\\ used as a C substrate but also various g substrates similar to this.

Furthermore, as for the material of the thin substrate, not only crystal, silicon, gallium arsenide, and aluminum, but also thin substrates made of lithium tantalate, etc. can be applied.

[Effects of the Invention] As explained above, according to the thin substrate manufacturing method of the present invention, since both sides of the thin substrate are processed by the same grinding means, the deteriorated layer produced by processing becomes uniform on both sides, and the double-sided polishing process etc., the manufacturing process for making the altered layer uniform can be omitted. As a result, it is possible to simplify the manufacturing process and shorten the manufacturing time, and it is also possible to manufacture a thin substrate with high precision and high quality without warping.

Furthermore, according to the thin substrate manufacturing apparatus of the present invention, the above method can be realized with a single mat, simplifying the manufacturing process and shortening the molding time, and producing thin substrates with higher precision and higher quality. can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the first embodiment of the undeveloped II thin substrate manufacturing apparatus, FIG. 2 is a front view of the same, and FIG. 3 is the arrow direction A-At! in FIG. 1. 1 is an enlarged view, FIG. 4 is a process diagram showing an embodiment of the thin substrate manufacturing method of the present invention, and FIG. 5 is a process diagram showing an embodiment of the thin substrate manufacturing method of the present invention. A plan view showing the second embodiment of t1, FIGS. 6 and 7 are a process diagram of a conventional thin substrate manufacturing method, and FIG.
), (b), and (c) are diagrams illustrating the occurrence of warpage in the conventional method. = 2 & stand 2: Feeding table: Moving table IO: Thin substrate cutting means Ni blade mounting frame 13 Ni blade: Ingot supporting means Two side ejection slide holder: Ingot: Thin substrate supporting means 33: Supporting member: Grinding means 43: Grinding wheel: f4 substrate transfer means 51: first transfer means 52: second transfer means 60: unloading cassette 61: unloading arm 64: displacement sensor 67: rotary dresser diagram

Claims (2)

[Claims] (1) The end face of the ingot is ground flat, then the end face side of the ingot is cut into thin pieces of a predetermined thickness, and the cut thin pieces are then inverted and attached to a chuck parallel to the cut surface to cut the thin pieces. A thin substrate manufacturing method characterized by grinding the surface. (2) an ingot support means for fixing and holding the ingot; a thin substrate cutting means for cutting the end surface side of the ingot whose end surface has been ground flat to a predetermined thickness; and a thin substrate cutting means for cutting the ingot into a predetermined thickness. a thin substrate supporting means that is capable of inverting and fixing the thin substrate with the cut surface facing up, and that is movable at least along the same path as the ingot supporting means; a thin substrate transfer means for inverting and transferring the thin substrate to the thin substrate support means; and an ingot fixed to the ingot support means, the ingot being provided opposite to the movement path of the ingot support means and the thin substrate support means; and/or a grinding means for grinding the end face of the thin substrate and/or the surface of the thin substrate fixed to the thin substrate supporting means.