JPS63310123A - Silicon semiconductor substrate - Google Patents

Abstract

PURPOSE:To maintain a gettering effect and, at the same time, to prevent a silicon particle from being exfoliated or from falling off by a method wherein a silicon layer or a silicon nitride layer is formed on the surface of a partially destroyed layer which has been formed mechanically or thermally on one face of a substrate. CONSTITUTION:After a mechanically or thermally partially destryed layer 4 has been formed on one face (the rear) of a semiconductor substrate 1, a silicon layer or a silicon nitride layer 5 is deposited on the rear by a PVD method (a physical vapor deposition method) or a CVD method (a chemical vapor deposition method) such as an evaporation method, a sputtering method or the like, and the surface of the partially destroyed layer 4 is covered. By this setup, while a gettering effect is maintained, it is possible to prevent a silicon particle from being exfoliated or from falling off during a process to manufacture a semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a silicon semiconductor substrate for manufacturing semiconductor devices.

(Prior Art) In the manufacturing process of a semiconductor device, if the surface of a silicon semiconductor substrate is contaminated with impurities, the characteristics of the semiconductor device will be significantly deteriorated and the yield will be reduced. As a countermeasure against this problem, a method has been implemented in which impurities are adsorbed to crystal defects inside a silicon semiconductor crystal or to a strained layer formed on the back surface of a silicon substrate. Hereinafter, the effect achieved by this method will be referred to as the gettering effect.

As methods for forming a strained layer on the back surface of the silicon substrate mentioned above, there are known methods such as shot blasting, which involves mechanical partial destruction or processing, methods such as polishing, and methods in which partial thermal destruction is applied using a laser or the like. ing. Hereinafter, processing using these methods will be referred to as back damage processing.

(Issuance 151 or the point to be solved) However, if the above hack damage treatment is adopted, the destroyed silicon particles of the silicon semiconductor substrate will peel off or fall off from the substrate during the hack damage treatment, or will fall off at this time. During the manufacturing process of semiconductor devices, the silicon particles that did not peel off or fall off from the back surface of the substrate due to external stress due to vibrations, thermal stress due to heat treatment, etching process, etc., and the silicon particles adhere to the surface of the silicon substrate, causing the semiconductor There is a problem in that the yield of device manufacturing decreases.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above problems, and employs the following technical means.

That is, a silicon semiconductor substrate used for manufacturing semiconductor devices, in which a partially broken layer is mechanically or thermally formed on one surface of the silicon semiconductor, and a silicon layer or a silicon nitride layer is formed on the surface of the partially broken layer. Its characteristic is that it is

(Function) On the surface of a silicon semiconductor substrate on which a partially destroyed layer has been formed by back damage treatment, it may peel or fall off due to external stress due to vibration etc. in the semiconductor device manufacturing process, thermal stress due to heat treatment, etching process, etc. According to the present invention, these unstable silicon particles are covered by the silicon layer or nitride film layer, thereby improving semiconductor device manufacturing while maintaining the gettering effect. This means that peeling and falling off of silicon particles can be prevented during the process.

(Example) Hereinafter, the present invention will be explained in further detail based on the drawings.

FIG. 1 shows a schematic cross-sectional view of a silicon semiconductor substrate according to the present invention. In FIG. 1, l is a silicon substrate, and a partially destroyed layer 4 is formed on one surface of the substrate 1 by back damage treatment. 3 is a strained layer formed by the partially destroyed layer 4; 5 is a silicon layer or a silicon nitride layer deposited by PVD or CVD.

More specifically, after forming a partially destroyed layer mechanically or thermally on one surface (hereinafter referred to as "back surface") of the semiconductor substrate 1 according to the present invention, the back surface is subjected to a vapor deposition method, a sputtering method, etc. P
A silicon layer or silicon nitride layer 5 is deposited using a VD method (physical vapor deposition method) or a CVD method (chemical vapor deposition method), and the surface of the partially destroyed layer 4 is is covered.

In the drawings, 2 indicates a defect-free layer and 3 indicates a strained layer.

The present inventor first investigated the crystal orientation (
A silicon semiconductor substrate with a surface of 100) is prepared, a partially destroyed layer is formed on the back side of the substrate by shot blasting, which is a type of back damage method, and a CVD process is applied to the back side of the substrate on which the partially broken layer is formed. A polycrystalline silicon layer of 0.5 mm thick, 1 pm thick, and 1.5 mm thick was covered by the method.

Next, the silicon semiconductor substrate produced by the above method was immersed in hydrofluoric acid, pulled up, and the contamination state of the substrate surface was observed. The results are shown in FIG. The vertical axis indicates the number of particles with a particle size of 0.25 mm or more measured by a surface inspection device, and the horizontal axis indicates the presence or absence of treatment and the type of treatment.

As is clear from Figure 2, the number of particles on the surface of the substrate without hack damage treatment is about 3 x 10, compared to 3 x 10 on the substrate with back damage treatment on the back side.
However, in the case of a substrate in which a polycrystalline silicon layer was covered with a hack damage layer using the CVD method, the thickness of the polycrystalline silicon layer was 0.5 μm, 1 μm thick, and 1.s , 102 pieces each for LL11, 5X
The number of particles was 10, 4x10. In other words, CV
By covering with a polycrystalline silicon layer using the D method, it is possible to prevent silicon particles from peeling off or falling off from the partially destroyed layer on the back side while maintaining the getterlink effect, and to prevent particles from adhering to the substrate surface. It was confirmed that

In the embodiment of the present invention, the back surface of the silicon semiconductor device is covered with a polycrystalline silicon layer formed by CVD method, or
A PVD method may be used instead of a CVD method, and a single crystal silicon, amorphous silicon, or silicon nitride layer may be used instead of a polycrystalline silicon layer.

(Effects of the Invention) As explained below, the present invention forms a partially destroyed layer mechanically or thermally on one surface of a silicon semiconductor substrate used for semiconductor device manufacturing, and forms a partially destroyed layer on the surface of the partially destroyed layer. It is constructed by forming a silicon layer or a silicon nitride layer, and while maintaining the gettering effect, it prevents silicon particles from peeling off or falling off, so it can suppress the adhesion of particles to the substrate surface during the semiconductor device manufacturing process. As a result, the yield of semiconductor device manufacturing is improved.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a silicon semiconductor substrate according to the present invention, and FIG. 2 is a diagram showing the relationship between a method for treating the back surface of a silicon semiconductor substrate and surface contamination particles. l...Silicon semiconductor substrate 4...Partially destroyed layer 5 due to backtaming treatment...
・Silicon layer or silicon nitride layer Patent applicant: Kyushu Electronic Metals Co., Ltd. Patent applicant: Osaka Titanium Manufacturing Co., Ltd. Representative: Patent attorney Tadashi Mori Manufacturing tube 1 Figure 1...Silicon semiconductor substrate 4...Partially due to backtaming treatment Destruction layer 5...
・Silicon layer or silicon nitride layer Figure 2

Claims (3)

[Claims] (1) A silicon semiconductor substrate used for manufacturing semiconductor devices, in which a partially destroyed layer is mechanically or thermally formed on one surface of the silicon semiconductor substrate, and a silicon layer or silicon nitride is formed on the surface of the partially destroyed layer. A silicon semiconductor substrate characterized in that a layer is formed. (2) The silicon semiconductor substrate according to claim (1), wherein the silicon layer or the silicon nitride layer is formed by a CVD (chemical vapor deposition) method. (3) The silicon semiconductor substrate according to claim (1), wherein the silicon layer or the silicon nitride layer is formed by a PVD (physical vapor deposition) method. (4) The silicon semiconductor substrate according to claim (1), wherein the silicon layer is polycrystalline.