JP2013258228A - Semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve bonding of a silicon substrate to a support medium without grinding of an outer periphery of the silicon substrate.SOLUTION: A semiconductor device manufacturing method according to the present embodiment comprises: a process of preparing a semiconductor substrate having a device layer on one surface side; an adhesion process of bonding the surface of the semiconductor substrate on the device layer side to one surface of a support medium; and a process of grinding, after the adhesion process, a surface of the silicon substrate on the side opposite to the one surface side. In particular, a depression processing is preliminarily performed before the adhesion process so as to make the surface of the bonding semiconductor substrate on the device layer side adhere tightly to the one surface of the support medium.

Description

  The present invention relates to a method for manufacturing a semiconductor device.

  FIGS. 6 to 8 show the transport state of a thin silicon wafer in the formation of a through silicon via (TSV), which is a three-dimensional mounting package technology for a semiconductor device.

  First, FIG. 6 shows a cross-sectional view of the transport state of the silicon substrate 1a before chip dicing. The substrate diameter of the silicon substrate 1a is reduced from 300 mm to 298.5 mm by grinding the outer periphery to prevent chipping after the back surface grinding. The silicon substrate 1a is also ground back to a thickness of 50 μm. A device layer 2 on which a semiconductor element is formed exists on the surface of the silicon substrate 1a. A silicon nitride film 3 for preventing Cu contamination from the back surface is formed on the back surface of the silicon substrate 1a.

  A TSV trench 7 penetrating the backside silicon nitride film 3 and the silicon substrate 1a is provided, and a backside bump 8 is formed so as to fill the inside.

  An adhesive 6 for protecting the outer periphery is applied to the surface of the silicon substrate 1a where the device layer 2 is present to a thickness of 50 μm, and the support 4 is made of glass or the like via the interposition layer 5 for adhesion and desorption. It is affixed to.

  In the above example, since the outer circumference of the silicon substrate 1a is ground, the area of the device layer 2 on the surface is also reduced, and the final product number is reduced. In addition, the adhesive 5 that protects the outer periphery is raised, and since the silicon substrate surface is not flat, the process uniformity is affected and the yield is reduced.

  In addition, since the adhesive is exposed from the edge of the silicon substrate, abnormal discharge is caused during processing using plasma discharge, and the yield is reduced.

  Next, a method for manufacturing the semiconductor device shown in FIG. 6 will be described with reference to FIGS.

  First, as shown in FIG. 7, a thickness of 675 μm and a diameter of 300 mm formed of glass or the like on the surface on which the device layer 2 of the silicon substrate 1 having a thickness of 775 μm and a substrate diameter of 300 to 298.5 mm is ground. The support 4 is affixed with an adhesive 6 having a thickness of 50 μm through an adhesion / detachment intervening layer 5.

  Next, as shown in FIG. 8, the back surface of the silicon substrate 1 is polished to a thickness of 50 μm to form a silicon substrate 1a. Thereafter, a backside silicon nitride film 3 for preventing Cu contamination is formed on the backside of the thinned silicon substrate 1a.

  Next, as described in FIG. 6, the TSV trench 7 penetrating the backside silicon nitride film 3 and the silicon substrate 1a is formed by using a dry etching method. Thereafter, a back bump 8 is formed so as to bury the TSV trench 7 inside.

JP 2009-1111061 A

  In the above semiconductor device, since the outer circumference of the silicon substrate 1 is ground, the area of the device layer 2 on the surface is also reduced, and the final number of products can be reduced. In addition, the adhesive 6 that protects the outer periphery is raised, and the surface of the silicon substrate 1a is not flat, thereby affecting the process uniformity and reducing the yield.

  Accordingly, an object of the present invention is to enable the bonding of the silicon substrate to the support body to be realized without the peripheral grinding of the silicon substrate.

  According to an aspect of the present invention, a step of preparing a semiconductor substrate having a device layer on one side, a bonding step of attaching a surface on the device layer side of the semiconductor substrate to one side of a support, and after the bonding step, Grinding the surface opposite to the one surface side of the silicon substrate, and before the bonding step, so that the surface on the device layer side of the semiconductor substrate to be adhered to the one surface of the support, A method of manufacturing a semiconductor device is provided, in which recessing is performed in advance.

According to the present invention, the following effects can be obtained.
(1) Since it is not necessary to grind the outer periphery of the silicon substrate, the area of the device layer on the surface of the silicon substrate does not decrease, and the final product number does not decrease.
(2) Since the silicon substrate surface can be flattened, there is no problem of affecting the process uniformity and reducing the yield.
(3) Since the adhesive is not exposed, abnormal discharge is caused during processing using plasma discharge, and the yield is not lowered.

It is sectional drawing which shows the conveyance state of the thin silicon wafer in three-dimensional mounting package technology of the semiconductor device by preferable embodiment of this invention in silicon penetration electrode formation. It is sectional drawing for demonstrating the sticking process of the support body which is a process before reaching FIG. It is sectional drawing which shows the state after support body sticking by the process of FIG. It is sectional drawing which shows the state after the BG process following FIG. FIG. 5 is a cross-sectional view for explaining the back-side silicon nitride film forming step continued from FIG. 4. It is sectional drawing for demonstrating the general example of the three-dimensional mounting package technique of a semiconductor device before chip | tip dicing. It is sectional drawing for demonstrating the sticking process of a support body which is a process before reaching FIG. FIG. 8 is a cross-sectional view for explaining the back surface silicon nitride film forming step continued from FIG. 7;

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  1 to 5 are cross-sectional views showing a transport state of a thin silicon wafer in forming a through silicon via (TSV), which is a three-dimensional mounting package technology for a semiconductor device according to the first embodiment of the present invention. is there.

  FIG. 1 shows a cross-sectional view of the state in which the silicon substrate 1a is transferred before chip dicing. The silicon substrate 1a is back-ground to a thickness of 50 μm with a substrate diameter of 300 mm. A device layer 2 on which a semiconductor element is formed is present on the surface of the silicon substrate 1a. A silicon nitride film 3 for preventing Cu contamination from the back surface is formed on the back surface of the silicon substrate 1a.

  A TSV trench 7 penetrating the backside silicon nitride film 3 and the silicon substrate 1 a is provided, and a backside bump 8 is formed so as to bury the inside of the TSV trench 7.

  An adhesive 6 for protecting the outer periphery is applied to the surface of the silicon substrate 1a where the device layer 2 is present to a thickness of 50 μm, and the support 4 is made of glass or the like via the interposition layer 5 for adhesion and desorption. It is affixed to.

  In consideration of the diameter of the silicon substrate 1a, the support 4 takes into consideration the thickness of the silicon substrate 1a after BG (Back Grind) and the coating thickness of the adhesive 6 to 50 μm. Indentation is performed in advance in a shape that closely contacts the surface of the device surface 2 of 1a (FIG. 2). This indentation can be performed by polishing, wet etching, dry etching, or a combination thereof.

  By doing so, since the silicon substrate 1a after the back surface grinding is embedded in the support 4, there is no need to grind the outer periphery, and the back surface of the silicon substrate 1a after the back surface grinding can be flattened. The protective adhesive will not rise.

  A method for manufacturing the semiconductor device shown in FIG. 1 will be described below with reference to FIGS.

  First, as shown in FIG. 2, a portion of the support 4 made of glass or the like and having a diameter of 300 mm and a thickness of 675 μm that is in contact with the silicon substrate 1 is recessed. This indentation process is performed in consideration of the R (R) portion of the outer periphery of the silicon substrate 1, the thickness of the silicon substrate 1a after the backside grinding of the silicon substrate 1, and the coating thickness of the adhesive 6 being 50 μm. It is performed so as to have a shape that is in close contact with the surface of the device surface 2 of 1a. This indentation can be performed by polishing, wet etching, dry etching, or a combination thereof. The thickness of the adhesion / desorption intervening layer 5 can be ignored.

  Specifically, a concave flat portion 4a having a depth of 100 μm is formed on one surface of the support 4 by combining the thickness 50 μm of the silicon substrate 1 a after back grinding and the coating thickness 50 μm of the adhesive 6.

  Next, as shown in FIG. 3, the surface on which the device layer 2 of the silicon substrate 1 having a thickness of 775 μm and the substrate diameter of 300 mm is present and the indentation flat part 4a of the indented support 4 are closely adhered and removed. It sticks with the adhesive agent 6 apply | coated to the thickness of 50 micrometers through the separation layer 5.

  Next, as shown in FIG. 4, the back surface side of the silicon substrate 1 is polished to a thickness of 50 μm. At this time, since the concave portion 4a having a depth of 100 μm is formed in the support 4 in advance, the support 4 can be formed without polishing the outer periphery of the polished silicon substrate 1a, that is, the outer end surface portion. On the other hand, it can be made flat.

  Next, as shown in FIG. 5, a backside silicon nitride film 3 for preventing Cu contamination is formed on the backside of the silicon substrate 1a.

  Next, as shown in FIG. 1, a TSV trench 7 penetrating the backside silicon nitride film 3 and the silicon substrate 1a is formed by using a dry etching method.

  Thereafter, a back bump 8 is formed so as to bury the TSV trench 7 inside.

  As described above, according to the first embodiment, since it is not necessary to perform peripheral grinding on the silicon substrate 1, the area of the device layer 2 on the surface of the silicon substrate is not reduced, and the final number of products can be obtained. Will not decrease. In addition, since the silicon substrate surface can be flattened, there is no problem of affecting the uniformity of the process or the yield is reduced, and the adhesive is not exposed. Occasionally, abnormal discharge is caused and the yield is not lowered.

  As mentioned above, although this invention was demonstrated about preferable embodiment, it cannot be overemphasized that this invention is not what is limited to the said embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the spirit and scope of the present invention described in the claims.

DESCRIPTION OF SYMBOLS 1, 1a Silicon substrate 2 Device layer 3 Back surface silicon nitride film 4 Support body 4a Indentation flat part 5 Adhesion | desorption interposition layer 6 Adhesive 7 TSV trench 8 Back surface bump

Claims (3)

Preparing a semiconductor substrate having a device layer on one side;
An adhesion step of attaching the device layer side surface of the semiconductor substrate to one surface of the support;
Grinding the surface on the opposite side of the one side of the silicon substrate after the bonding step,
Prior to the bonding step, the semiconductor device manufacturing method is characterized in that indentation is performed in advance so that a surface of the semiconductor substrate to be attached is in close contact with one surface of the support.   2. The semiconductor device according to claim 1, wherein the indentation is performed to a depth that takes into account the thickness of the semiconductor substrate and the thickness of the adhesive after grinding of the opposite surface. Manufacturing method. After the grinding process of the opposite surface,
Forming a silicon nitride film on the opposite surface of the semiconductor substrate;
Forming a TSV trench penetrating the silicon nitride film and the semiconductor substrate;
Forming a back bump to bury the TSV trench interior;
The method for manufacturing a semiconductor device according to claim 1, wherein:

Images