JPS58164229A - Treatment of semiconductor substrate - Google Patents

Abstract

PURPOSE:To remove rapidly a crystal defect, mainly a stacking defect and a generating nucleus thereof by a method wherein a heat treatment is performed to a semiconductor substrate in an inactive gas atmosphere or a plasma atmosphere containing NH3 and a hydrazine group or NH3 or hydrazine. CONSTITUTION:When the heat treatment is to be performed to the semiconductor substrate to remove the stacking defect, the Si crystal substrate is treated in the inactive gas atmosphere or the plasma atmosphere containing NH3 and hydrazine group or NH3 or the kind of hydrazine. At this time, a hydrazine salt of N2H4, N2H4.HCl, etc., is used, and as inactive gas containing NH3 and/or the kind of hydrazine, N2 gas or Ar gas is used. Moreover the treatment temperature is set at 1,150-1,200 deg.C, and length of the defect is reduced in a short nitriding time. Accordingly removement of the generating nucleus of the defect is attained without generating roughness and contamination of the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the semiconductor substrate 1 [4611 method, and IK*m includes, for example, the conductor substrate processing II.
It is about law.

For example, in an image sensor such as a silicon crystal substrate (CCN), stacking faults in the 4111 m8 crystal that serves as the substrate cause image defects.1 A huge amount of research has been devoted to removing the stacking faults. We met. For example, it has been known that crystal defects existing on the crystal surface imz<E or the generation nuclei of crystal defects can be removed from a hot layer in an inert gas such as nitrogen gas or argon gas. In other words, a method of annealing a single piece of mengo crystal in high-temperature nitrogen gas, argon gas, or hydrogen gas has been put into practical use. Crystal defects and stacking faults can be removed quickly in high-temperature layers (and in N! gas. Recently, KHCJFIIM in %N2 gas has been used to remove stacking faults faster than in a tube). Is there a way to do this in I1 prefecture?!E.

However, N, argon, water bulk gas or Hcj
The high-temperature stratum in horse gas added with silicon*WJK
, is also the cause of J [which causes @ (inho ka ji enie tei). In addition, 110 (more than 1 N!) 7 ms in the gas atmosphere is due to the already existing stacking fault model 1I
Although it has the effect of exclusively annihilating Ia, it creates new K (also known as C) that creates more stacking fault nuclei.

This phenomenon is caused by the formation of stacking fault generation nuclei 6 when observing the crystal surface using the aforementioned heating layer.
This is to provide a layer f for removing stacking faults and their generated nuclei in fL.

The method of this invention consists of heating a semiconductor substrate made of silicon crystal in an atmosphere of NHs, hydrazine, or a non-S* gas containing NHl or hydrazine, or in plasma 111. Examples of hydrazines used in the method related to 1 include hydrazine salts such as N2H4s, N2H4'', etc. 1@(, and/or inert gases containing hydrazines include s N2, argon gas, etc. Etc. 188 times.

The method according to this invention was studied as follows.

First, dry the silicon crystals! 1 at 1100C inside
The silicon wafer was oxidized for 6 w# to form a silicon wafer having stacking faults of Ik 60 ms. In this case, one set of genus 02 is 55
He grew up to be a 00m thick college student.

As shown in Section 11iii, this sample was treated by changing the partial pressure of the group ink from 5kl/cs'' to 10-#I4/J by 7.
411=temperature J611t at 150C. For specific softness, the sample was heated under conditions of zero partial pressure. Iris 1
In case of heat treatment using a sample with 8102 film (5soojL) on the wafer surface shown by - line A in a, it is hidden that stacking faults grow as the partial pressure of %NH decreases. It will be done. In addition, as shown by self-lsB, in Uniru bar without 5tO2 film on the surface, NH3
It is observed that as the partial pressure (fullness) increases, the stacking faults shrink rapidly. 1150t: 'NH for 5 hours
.

During heat treatment, complete disappearance of the Nanaso-Sekan stacking faults was often observed. On the other hand, N2 heat treatment under these conditions was recommended for more than 10 hours, so Significant time savings are possible.

Next, we changed the thickness of the 8-layer 02 film in the sample number used, and 4
The length of the stacking fault was determined by heat treatment for each time #j. The results are shown in FIG. In FIG. 2, the - line C indicates heat treatment at 1150 tl', the curved line indicates heat treatment at 1100C, and the curve E indicates heat treatment at 1050C. From these results, it can be seen that 810
．． It was found that unless the initial thickness of the film was about 1,501 mm or less, there was no effect of suppressing stacking faults, and that stacking faults did not occur in the absence of the 02 film.

In addition, using the sample used in Fig. 2, the initial 5i
The density of stacking faults was measured when the O2 film thickness and heat treatment temperature were changed, and the results are shown in FIG. From these results, the initial 810° film thickness is approximately 150A.
If the stacking faults are not less than 'FilI1
4t.

Furthermore, using a silicon crystal sample with a 5,500 μm thick fs102 film and a silicon crystal sample without an '8!02 film, we investigated the treatment time with NHL or hydrazines, that is, the nitriding treatment time, and the length of stacking defects/defects. I investigated the relationship between The results are shown in 4th rIA. In addition, in the figure, - lines F to ■ indicate heat treatment temperatures of 1050 U and 1, respectively.
100G, 1150t:' and 1200t:', and - lines J to L indicate heat treatment temperatures of 1050C and 1200C, respectively.
1100C edict and 1150C are shown. According to the results in FIG. 4, 810. Silicon crystals that do not have a film can be heat treated at high temperatures.

For example, by processing at 1150G to 1200G, the length of stacking faults can be shortened with a short nitriding time, whereas 810. In a silicon crystal with a film, heat treatment at 1050U increases the length of stacking faults, and at a high temperature of 1150C, even if the nitriding time is short, stacking faults do not grow. It turns out that it happens quickly. That is, by heat treatment in a high-temperature atmosphere such as NHs, silicon oxynitride of several tens of amperes is formed on the surface of a silicon crystal, and this film becomes a protective film that protects the surface of a semiconductor substrate made of silicon crystal. Keeps it smooth and clean.

As mentioned above, according to the medium conductor substrate processing method according to the present invention, the problems of surface roughness and contamination in the removal of crystal defects and generation nuclei of crystal defects caused by conventional high-temperature treatment can be solved, and The desired effect can be achieved more quickly.

[Brief explanation of drawings]

1 to 4 are graphs showing the conditions of the method according to the present invention, respectively. Agent Masaru Ueya Figure 3 Ne71 Its R5t (h Ill (A) Figure 4

Claims (1)

[Claims] A method for manufacturing conductor substrates in which a semiconductor substrate is exposed to NHs1 hydrazine or hydrazine 1llf in a gas atmosphere or in a plasma atmosphere.