JPH0485938A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent substrate surface pollution by using an HLD film as the channel through film at formation of the source and drain regions of a MOS field effect transistor. CONSTITUTION:A gate material is formed through a thermal oxide film on one main surface of an Si substrate 1, and this is patterned to form a MOS gate 2, and the pollutant on the surface is removed and cleaned by the means such as dry etching, etc., and then it is heat-treated. Next, an HLD film 5 is made on the whole face. This HLD film 5 wraps the gate part 2, and is formed as a thin insulating film at the surface of the substrate 1. And after deposition of the HLD film, heat treatment is performed, and then ions of impurities are implanted into the surface of the substrate through the HLD film, and source and drain regions are diffused. Next, an interlayer insulating film or an HLD film 6 as a passivation film is formed thick at the whole face. And an window is made in the interlayer film 6, etc., and an Al electrode 7 is made at the source and drain regions. Hereby, the pollution of the surface of the substrate can be prevented, and the inferiority such as surface leak reduced, and the reliability of a product improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique for preventing contamination on the surfaces of source and drain regions during the manufacture of semiconductor devices such as MO3 field effect transistors.

[Conventional technology]

One of the conventional methods for forming MOS transistors on the surface of a semiconductor substrate (wafer) is to apply a conductor such as polysilicon or metal to the substrate surface via a thermal oxide film, either singly or in M layers. This is used as part of a mask pattern to perform gate patterning to form an insulated gate. After cleaning the substrate surface, a thin thermal oxide film is formed on the entire surface by light oxidation, and impurities are removed through this thin thermal oxide film. The source/drain regions are formed by ion implantation into the semiconductor surface.

[Problem to be solved by the invention]

- According to the above-mentioned conventional method, polysilicon or the like that has been treated with phosphorus to make it conductive is used for the gate, and the phosphorus in the gate causes out-difference due to heat treatment after gate processing, resulting in gate M % was incorporated into the surface of the substrate, causing n inversion and causing surface leakage.

In addition, conventionally, the solution was to use an etch technique that leaves a certain amount of gate film on the substrate during gate dry etching, but
In this method, the W that forms part of the gate after gate processing is
Heavy metal contamination such as tungsten (tungsten) is likely to occur on the substrate surface, and when cleaning to remove this contaminant, residual oxidation must be taken into consideration, which limits the cleaning conditions.

The present invention has been made to solve the above-mentioned problem, and its purpose is to protect semiconductor devices from surface contamination.Another purpose of the present invention is to protect semiconductor devices from surface contamination. The purpose of this invention is to prevent defects in semiconductor devices such as leakage defects.

[Means to solve the problem]

To achieve the above object, the present invention is one of the semiconductor substrates.
An insulated gate is formed on one surface, and after the surface is cleaned to remove contamination, the insulated gate is covered with a thin semiconductor oxide deposited film.
The present invention relates to a method of manufacturing a semiconductor device, characterized in that impurities are then diffused onto the surface of the semiconductor substrate through the thin oxide deposited film to form source/drain regions.

The present invention provides the method for manufacturing a semiconductor device, wherein the semiconductor oxide deposited film is produced under high pressure and low temperature conditions through a chemical reaction.

The present invention also provides the above method for manufacturing a semiconductor device, in which the entire surface behind the source/drain regions is covered with a thick semiconductor oxide deposited film produced by chemical reaction under high pressure and low temperature conditions.

[Effect]

An insulated gate is processed on a semiconductor substrate, and impurities and heavy metals from the gate are removed by covering the entire surface with a waxy oxide film using HLD (high pressure low temperature deposition) technology. It can be used as an impurity-permeable membrane when the surface of the conductor is filled with non-contaminated materials like conventional heat-oxidized glands, without introducing new contamination due to
・The formation of the North Train @ region is considered to be a function of the mouth.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the present invention.

FIG. 1 is a flowchart of the manufacturing process of MO8 field effect transistor according to conventional specifications, and in contrast,
This is for explaining the present invention.

FIGS. 2(a) to 2(c) are cross-sectional views of main parts corresponding to the process of FIG. 1.

In the conventional specification, first, as shown in Fig. 2(a), Si
A gate material was formed on one main surface of the substrate 1 via a thermal oxide film, and the MOS gate 2 was formed by patterning, and the surface was cleaned and contaminants were removed by means such as dry etching. Afterwards, heat treatment is performed. In this example, gate part 2
uses a two-layer structure in which a WSiz film is stacked on a poly-Si film. In this case, heat treatment is performed to improve adhesion so that the WSiz layer at the gate part does not peel off in the next surface oxidized lIQ cedar culm.

In the next step, light thermal oxidation is performed to form a thin thermal oxidation ff3 (approximately 100 layers) on the substrate surface. During this heat treatment, W
There was a risk that contamination such as Siz would be introduced into the substrate.

Thereafter, using the gate portion as a mask, impurities are ion-implanted or diffused into the substrate 1 through the thermal oxide film 3 to form source/drain regions.

FIG. 3 is a flowchart 1 of the manufacturing process of an MO3 electric field transistor according to the specifications of the present invention.

FIGS. 4(a) to 4(d) are cross-sectional views of main parts corresponding to the process shown in FIG. 3.

According to the specifications of the present invention, the MOS gate processing and contamination removal cleaning steps shown in FIG. 4(a) are the same as in the conventional process, but after this, the HL
, Dxin (silicon oxide 1t by commercial pressure low salt chemical deposition)
5 is formed on the entire surface. The Hl and DI*5 wrap around the gate portion 2 and are formed as an insulating film 7 on the surface of the substrate 1 with a thickness of approximately 150 mm. With a thickness of this level, it is possible to prevent contamination even if heat treatment is performed after H1, I) He deposition, and direct implantation to the gate can be prevented, and implantation on the WSiz surface of the gate can be prevented. This has the effect of preventing WSi2 peeling due to damage reduction, and it is also possible to implant impurities (ion implantation) into the substrate through this film.

According to the specifications of the present invention, heat treatment is performed after HLD film debossing, and then the HLD film is heated as shown in FIG. 4(c).
Impurity ions are implanted into the substrate surface through L D M % to diffuse the source/drain regions 4 .

Note that after the above process, as shown in FIG. 4(d),
7. H with insulation crotch or panhesion vagina on the entire surface
Each time the LD film 6 is formed sufficiently thick.

FIG. 5 is a sectional view showing the completed form of a transistor in which AA electrodes 7 are formed in resistive contact with the source/drain regions using the interlayer frame 6 and the like as a window.

Figure 6 shows an applied embodiment of the present invention, in which H is connected to the gate.
LDD with side walls (spacers) 8 formed by L, D, etc.
This figure shows an example in which the present invention is applied to a type device.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

HLDItl is the source of the MO3 field effect transistor.
By using it as a channel through film when forming a drain region, it is possible to prevent substrate surface contamination that occurs when forming a conventional thermal oxide film.

In addition, when a metal with high stress such as W is used for a part of the gate, the HLD film acts as an implant through H9 (
Therefore, damage such as peeling of the surface can be prevented by one bond, and it has the effect of stress relaxation. Furthermore, due to the effect of preventing contamination on the substrate surface, defects such as surface leakage of MOS field effect transistors can be reduced, and product reliability can be expected to be improved.

■...f conductor base, 2...insulated gate, :3...
・Thermal oxide film, 4...source/drain'iif!
Area, 5--Light HL, I) g*, 6-#,
IHL l) Hl

[Brief explanation of drawings]

FIG. 1 is a flowchart of the manufacturing process of a conventional MO3 semiconductor device. 2(a) to 2(c) are process cross-sectional views corresponding to the process of FIG. 1. FIG. 3 is a flowchart of the manufacturing process of an MO3 semiconductor device according to the specifications of the present invention. 4(a) to 4(d) are process sectional views corresponding to the process of FIG. 3. FIG. 5 is a cross-sectional view during electrode formation performed subsequent to the step of FIG. 4(d). FIG. 6 shows an applied embodiment of the present invention.1. , DD is a sectional view of a main part of a D-type semiconductor device. Fig. 1-4 J-I, r+1-r9 2-Ray L-Il to 3-41? 4--,, / -, Z t = L , r > j-se 5 D-ttjr'-: 6-special, \HLD low (

Claims (1)

[Claims] 1. An insulated gate is formed on one main surface of a semiconductor substrate, and after the surface is cleaned to remove contamination, the surface of the substrate including the insulated gate is covered with a thin semiconductor oxide deposited film, and then the thin film is deposited. 1. A method of manufacturing a semiconductor device, comprising the step of diffusing impurities onto the surface of a semiconductor substrate through an oxide deposited film to form source/drain regions. 2. In the method for manufacturing a semiconductor device according to claim 1,
The semiconductor oxide deposited film is produced under high pressure and low temperature conditions through a chemical reaction. 3. In the method of manufacturing a semiconductor device according to claim 1 or 2, after forming the source/drain regions, the entire surface is covered with a thick semiconductor oxide deposited film produced by chemical reaction under high pressure and low temperature conditions.