JP2006202802A - Process for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for manufacturing a semiconductor device in which reduction in size and thickness can be realized by a simple process. <P>SOLUTION: After a semiconductor substrate 1 is half cut and an isolation trench 3 is formed in advance, the semiconductor substrate 1 is secured by means of an adhesive film 4 and then separated by grinding the second major surface side of the semiconductor substrate 1 opposing the adhesive film 4. A simple process for manufacturing a semiconductor device not requiring a troublesome step for bonding the semiconductor substrate and a dielectric substrate and free from a factor for blocking reduction in size and thickness of a finished product of semiconductor device is thereby attained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a small and thin surface mount type semiconductor device.

  As a conventional method for manufacturing a semiconductor device, a technique is used in which a mirror-polished semiconductor substrate and an insulating substrate are directly bonded to each other in order to obtain a dielectric separation substrate. That is, when the mirror-polished substrates are brought into close contact with each other in a clean atmosphere substantially free of foreign substances, and a heat treatment is performed at a temperature of 200 ° C. or higher, a strong bonded substrate can be obtained. The insulating substrate may be either a substrate in which an insulating film is formed on the surface of the semiconductor substrate or a substrate made entirely of a dielectric. In this way, a desired element is formed on the substrate separated in the vertical direction, and a groove is formed on the semiconductor substrate side and the groove is filled with an amorphous material in order to separate the elements in the horizontal direction. (For example, see Patent Document 1).

  FIG. 2 shows a conventional method of manufacturing a semiconductor device described in Patent Document 1.

  2A to 2E, 101 is a first N-type silicon substrate, 102 is a high-concentration N-type layer, 103 is a second N-type silicon substrate, 104 is a first oxide film, and 105 is high. The concentration P-type layer, 106 is an element isolation trench, 107 is passivation glass, and 108 is a second oxide film.

  As shown in FIG. 2A, phosphorus is diffused on the polishing surface of the first N-type silicon substrate 101 to form a high-concentration N-type layer 102, and the polishing surface of the second N-type silicon substrate 103 is formed on the polishing surface. 2 forms a first oxide film 104 by wet oxidation, and the surface roughness of each surface of the high-concentration N-type layer 102 and the first oxide film 104 is 500 mm or less, as shown in FIG. After directly bonding the polished surfaces, heat treatment is performed to increase the adhesive strength, and as shown in FIG. 2C, the first N-type silicon substrate 101 is wrapped to adjust the thickness, and then boron is diffused. As shown in FIG. 2 (d), the entire surface is covered with a second oxide film 108, and a high-concentration N-type layer is formed from the high-concentration P-type layer 105 using a diamond saw. An element isolation groove 106 reaching the upper surface of 102 is formed to remove the crushed layer, as shown in FIG. In Suyo, by electrophoresis firing by filling a lead-based passivation glass 107 in the element isolation trenches 106.

Thereafter, a contact hole (not shown) was opened and Al wiring (not shown) was applied to form a diode array.
Japanese Examined Patent Publication No. 6-58934

  However, in the above-described conventional configuration, the second N-type silicon substrate 103 having the first oxide film 104 on the bonding surface that becomes the dielectric isolation substrate before element isolation is replaced with the first N-type silicon substrate 101. The high-concentration N-type layer 102 formed on the adhesion surface must be adhered, but at that time, the surface roughness of the adhesion surface between the first oxide film 104 and the high-concentration N-type layer 102 is polished to a mirror surface of 500 mm or less. It is necessary to heat-treat the surfaces together, which is cumbersome and time consuming, and the need for the second N-type silicon substrate 103 is a factor that hinders the thinning of the finished device. Was.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device that has a simple process and does not hinder thinning as a completed semiconductor device.

  In order to solve the above-described conventional problems, a semiconductor device manufacturing method of the present invention includes a plurality of semiconductor element formation regions on a first main surface side of a semiconductor substrate in a semiconductor device having an electrode on one side surface, Half-cut vertically and horizontally from the first main surface of the semiconductor substrate to form element isolation grooves between the respective semiconductor element formation areas, including the element isolation grooves and the semiconductor element formation areas An element separation step of attaching and fixing an adhesive film on the first main surface of the semiconductor substrate, adjusting the thickness by grinding from the second main surface side of the semiconductor substrate, and forming an element separation groove on the second main surface of the semiconductor substrate A grinding process for opening and completely separating and fixing the semiconductor substrate on the adhesive film, and an intermediate product obtained in the grinding process using a mold and a molding resin, and a second main surface of the semiconductor substrate and the element Adhesive film including separation groove A mold process for forming a mold resin covering the mold, an electrode forming process for peeling and removing the adhesive film to form an electrode on the external contact planned portion of the semiconductor element formation region, and a first main surface of the mold resin. Dicing up to two main surfaces and providing dicing gaps in the vertical and horizontal directions to separate the semiconductor device as a finished product in which the side surface of the semiconductor substrate including the semiconductor element formation region and electrodes and the second main surface are covered with mold resin. And a semiconductor device manufacturing method including a completed separation step.

  With this configuration, the semiconductor substrate is half-cut in advance to form an element isolation groove, and then fixed with an adhesive film, and the second main surface side of the semiconductor substrate facing the adhesive film is ground and separated. A process for bonding the semiconductor substrate and the dielectric substrate is not required, and the manufacturing method of the semiconductor device can be simplified and can be a semiconductor device completed product without causing a factor to reduce the thickness.

  As described above, according to the method for manufacturing a semiconductor device of the present invention, it is possible to provide a method for manufacturing a semiconductor device that is simple and does not hinder thinning as a completed semiconductor device.

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

  1A to 1F are cross-sectional views along a flow of a method for manufacturing a semiconductor device in an embodiment of the present invention.

  1A to 1F, 1 is a semiconductor substrate, 2 is a semiconductor element formation region, 3 is an element isolation groove, 4 is an adhesive film, 5 is a mold resin, 6 is a solder electrode, 7 is a dicing gap, 8 Indicates semiconductor devices, respectively.

  FIG. 1A is a cross section showing a state in which a semiconductor element formation region 2 is provided on the first main surface side of the semiconductor substrate 1.

  Further, the surface including the semiconductor substrate 1 and the semiconductor element formation region 2 is covered with a passivation film (not shown) such as an oxide film, and the passivation film on the external contact planned portion of the semiconductor element formation region 2 is removed to form a window. (Not shown) is formed.

  FIG. 1B shows a semiconductor device in which a half-cut is made vertically and horizontally from the first main surface of the semiconductor substrate 1 shown in FIG. An element isolation groove 3 is formed between the element formation region 2 and the semiconductor element formation region 2, and an adhesive film 4 is attached to the first main surface of the semiconductor substrate 1 including the semiconductor element formation region 2 and the element isolation groove 3. The cross section at the time of the end of the element isolation process to be fixed is shown.

  In FIG. 1C, the semiconductor substrate 1 is grounded from the second main surface side of the semiconductor substrate 1 shown in FIG. A cross-section at the end of the grinding process in which the groove 3 is opened on the second main surface of the semiconductor substrate 1 and completely separated and fixed on the adhesive film 4 is shown.

  FIG. 1 (d) shows a thermosetting type for semiconductors whose main component is epoxy, in which an intermediate product at the end of the grinding step shown in FIG. 1 (c) is closed and heated in a mold (not shown). A mold resin (not shown) is poured into a mold (not shown) and cured, and then taken out from the mold (not shown), and includes a second main surface of the semiconductor substrate 1 and an element isolation groove 3. The cross section at the end of the molding process for forming the mold resin 5 on the top is shown.

  In FIG. 1E, after the molding step shown in FIG. 1D is completed, the adhesive film 4 is peeled and removed, and a plating method or dipping is performed on the external contact planned portion of the semiconductor element formation region 2 described in FIG. The cross section at the time of completion | finish of the electrode formation process which forms the solder electrode 6 is shown.

  In FIG. 1F, after the electrode formation step shown in FIG. 1E is completed, the first principal surface to the second principal surface of the mold resin 5 are diced vertically and horizontally between the semiconductor substrates 1 with a dicing saw or the like. To separate the semiconductor device 8 which is a finished product in which the mold resin 5 covers the side surface and the second main surface of the semiconductor substrate 1 including the semiconductor element forming region 2 and the solder electrode 6. The cross section at the time of completion | finish of the completion separation process to be shown is shown.

  According to this configuration, the semiconductor substrate 1 is half-cut in advance to form the element isolation groove 3 and then fixed with the adhesive film 4 so that the second main surface side of the semiconductor substrate 1 facing the adhesive film 4 is disposed. Since it is ground and separated, a complicated process such as bonding of the semiconductor substrate and the dielectric substrate is not required, and the manufacturing method of the semiconductor device is simple and does not hinder thinning as a finished semiconductor device. Can do.

  In the present embodiment, the semiconductor device 8 is individually separated by the dicing gap 7 in the minimum unit of the semiconductor element in the completed separation step shown in FIG. A semiconductor device 8 having two or more semiconductor elements may be used.

  It is useful as a method for manufacturing a small and thin semiconductor device, and is particularly suitable for a surface mount type semiconductor device.

Sectional drawing along the manufacturing flow of the semiconductor device in embodiment of this invention Sectional view along the manufacturing flow of a conventional semiconductor device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Semiconductor element formation area 3, 106 Element separation groove 4 Adhesive film 5 Mold resin 6 Solder electrode 7 Dicing gap 8 Semiconductor device 101 First N-type silicon substrate 102 High concentration N-type layer 103 Second N-type silicon Substrate 104 First oxide film 105 High-concentration P-type layer 107 Passivation glass 108 Second oxide film

Claims (2)

In a semiconductor device having an electrode on one side,
Each of the semiconductor element forming regions has a plurality of semiconductor element forming regions on the first main surface side of the semiconductor substrate, and is subjected to a half-cut from the first main surface of the semiconductor substrate deeply and vertically to the semiconductor element forming region. An element separation step of forming an element isolation groove between the first and second semiconductor substrate including the element isolation groove and the semiconductor element formation region, and attaching and fixing an adhesive film on the first main surface;
Grinding from the second main surface side of the semiconductor substrate to adjust the thickness, and opening the element isolation groove on the second main surface of the semiconductor substrate to completely separate and fix the semiconductor substrate on the adhesive film Process,
A molding step of forming a molding resin that covers the adhesive film including the second main surface of the semiconductor substrate and the element isolation groove using the molding resin as an intermediate product obtained in the grinding step;
An electrode forming step of peeling off the adhesive film and forming an electrode on the external contact planned portion of the semiconductor element forming region;
Dicing from the first main surface to the second main surface of the mold resin to provide a dicing gap in the vertical and horizontal directions, the side surface of the semiconductor substrate including the semiconductor element formation region and the electrode, and the second main surface A method of manufacturing a semiconductor device, comprising: a complete separation step of individually separating the semiconductor device as a finished product covered with the mold resin. The semiconductor device including two or more semiconductor elements is used as a minimum unit of the semiconductor substrate including the semiconductor element formation region and the electrode when the dicing gap is provided and separated individually. Item 14. A method for manufacturing a semiconductor device according to Item 1.

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