JPH01160037A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce one part of an oxide film existing on the interface of a semiconductor substrate and a deposited thin-film, and to remove oxygen in the oxide film by a diffusion from the oxide film by depositing the thin-film onto the substrate in an atmosphere containing a reducing element, introducing the reducing element into the thin-film and annealing the whole. CONSTITUTION:Silicon 3 is deposited onto silicon substrates 1 through a chemical vapor growth method in a chamber 8. Silicon 3 is deposited onto the silicon substrates 1 by introducing monosilane gas (SiH4), keeping a temperature in the chamber 8 at 550-650 deg.C. When hydrogen 5 is induced into the chamber 8 as a reducing element in addition to SiH4 4 at that time, hydrogen 5 is introduced on the interfaces of the silicon substrates 1 and deposited silicon 3 and into silicon 3. Silicon 3 is deposited, and annealing using the infrared radiation 11 of a lamp electric furnace 10 is conducted in an Ar atmosphere to the silicon substrates 1 and deposited silicon 3. Accordingly, oxide films on the surfaces of the substrates can easily be removed through annealing.

Description

[Detailed description of the invention] to 2-7 Industrial applications The present invention relates to a method of manufacturing a semiconductor device.

Conventional technology Conventionally, before depositing a thin film on a semiconductor substrate, the oxide film formed on the surface of the semiconductor substrate is dissolved and removed using an etching solution, thereby removing the oxide film existing at the interface between the semiconductor substrate and the deposited thin film. was being removed.

FIG. 3 shows this conventional method, in which 1 is a silicon substrate. 13 is, for example, hydrofluoric acid and water 1 = 20
This is an etching solution made by mixing in a volume ratio of 14
is a container for storing the etching solution 13, and is usually made of Teflon or the like which is insoluble in hydrofluoric acid.

In the conventional method configured as described above, the container 1
The silicon substrate 1 is immersed in the etching solution 13 in the etching solution 4 for an appropriate period of time. The oxide film 2 formed on the surface of the silicon substrate 10 is dissolved in the etching liquid 13 and removed from the surface of the silicon substrate 1.

3,-7 Such methods are described, for example, in Journal of Applied Physics, Volume 57° Number 4,1.
5 (1985) February, pp. 1322-1327 (J,
Appl, Phys, 57 (4).

15 February 1985 PP 1322
-1327).

Problems to be Solved by the Invention However, in the above method, even if the oxide film 2 existing on the surface of the silicon substrate 1 is removed in the etching solution 13, the silicon substrate 1 cannot be removed from the etching solution 13 afterwards. There was a problem in that when the silicon substrate 1 was taken out and brought into contact with the atmosphere, the surface of the silicon substrate 1 was immediately oxidized by oxygen in the atmosphere.

Means for Solving the Problems The present invention solves the above-mentioned problems by depositing a thin film on a semiconductor substrate in an atmosphere containing a reducing element, and depositing a reducing element in the thin film. This method uses a method in which a material is introduced and then annealing is performed.

By depositing a thin film on a semiconductor substrate in an atmosphere containing elements that have action reducing properties, some of the elements that have reducing properties can be removed.
When introduced into the interface between the semiconductor substrate and the deposited thin film, and into the thin film, and annealed after the deposition of the thin film, the reducing element reduces at least the oxide film present at the interface between the semiconductor substrate and the deposited thin film. This makes it possible to partially reduce the oxygen in the oxide film and remove it from the oxide film by diffusion.

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

First Embodiment A first embodiment of the present invention will be described with reference to FIG. In this embodiment, silicon 3 is deposited on a silicon substrate 1 in a chamber 8 by chemical vapor deposition. Silicon 3 increases the temperature inside chamber 3 from 550°C to 650°
CKi is deposited on the silicon 5 silicon substrate 1 by introducing monosilane gas (SIH4). At this time, in addition to S I H44, hydrogen 5 is added to the chamber 8 as a reducing element.
When introduced into the silicon substrate 1 and the deposited silicon 3
Hydrogen 5 is introduced into the interface and into the silicon 3.

After depositing the silicon 3, the silicon substrate 1 and the deposited silicon 3 are annealed using infrared radiation 11 from a lamp electric furnace 1o, for example, in an Ar atmosphere. The optimum annealing conditions are 900'C to 1200'C and the optimum time is 1 second to 10 minutes.

By annealing, the interface between silicon substrate 1 and silicon 3,
The hydrogen 5 contained in the silicon 3 reduces and removes at least a portion of the oxide film 2 present at the interface between the silicon substrate 1 and the silicon 3 (arrow b). In this way, the oxide film on the surface of the substrate can be easily removed by annealing.

Figure 4 shows the experimental data. It can be seen in A-7 that the oxide film 2 is present at the interface of the deposited silicon substrate 1. A part of the oxide film 2 is reduced and removed by annealing at 1100° C. for 30 seconds.

In this way, the silicon substrate 1 and the deposited silicon 3
By reducing and removing the oxide film 2 present at the interface, for example, when silicon 3 deposited on the silicon substrate 1 is used as a wiring, electrical contact between the silicon substrate 1 and the silicon 3 can be made with low resistance. becomes possible.

@2 Embodiment A second embodiment of the present invention will be described with reference to FIG. In the figure, 1 is a silicon substrate, 2 is an oxide film, and 3 is a silicon substrate.
is silicon deposited in an atmosphere containing hydrogen 5, and the above structure is similar to that shown in FIG. The method for forming the silicon 3 may be a method other than the chemical vapor deposition method described in the first embodiment, such as a spunter method. The difference from the configuration shown in FIG. 1 is that an ArCW laser beam 12 is used as the annealing method.

A for silicon 3 deposited on silicon substrate 1
The rCW laser beam 12 is irradiated and heated under the conditions of, for example, an output of 7, a vane of 10 W, a beam diameter of about 100 μm on the sample surface, and a scanning speed of 1 ocm/sec. This allows A
The hydrogen 5 present in the interface between the silicon substrate 1 and silicon 3 and in the silicon 3 in the area irradiated with the rCW laser beam 12 removes at least a portion of the oxide film 2 present at the interface between the silicon substrate 1 and silicon 3. Reduce and remove.

Note that in the second embodiment, the ArCW laser beam 12
was used as a high-energy beam, but instead of irradiating the ArCW laser beam 12, an ion beam, for example, a silicon ion beam, was used as a high-energy beam.
A similar effect can be obtained by irradiating with an electron beam at 10 mA/7, 6 KeV, and a scanning speed of 10 m/sec.

At this time, the pressure of the atmosphere is reduced to about 10-5 Torr.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, at least a part of the oxide film existing between the semiconductor substrate and the deposited thin film can be reduced and removed after the thin film is deposited, which is an excellent feature in semiconductor devices. It becomes possible to demonstrate practical effects.

[Brief explanation of the drawing]

FIG. 1a is a cross-sectional structural diagram of a thin film deposition apparatus used in the thin film deposition process of the present invention, FIG. 1 is a cross-sectional process schematic diagram of the annealing process of the first embodiment of the present invention, and FIG. A cross-sectional process schematic diagram of the annealing process of the second embodiment, FIG. 3 is a cross-sectional process schematic diagram of the conventional etching process for removing the oxide film,
FIG. 4 is an impurity distribution characteristic diagram obtained by measuring the hydrogen and oxygen concentrations before and after annealing at 110° C. for 930 seconds using a secondary ion mass spectrometer. 1...Silicon substrate, 2...Oxide film, 3.
...Deposited silicon, 1o...Lamp N'
X Furnace. Name of agent: Patent attorney Toshio Nakao and 1 other person - Yoko W&S Figure 2 Figure 4: 308 Figure 3...h's゛N''

Claims (4)

[Claims] (1) A semiconductor device comprising the steps of: depositing a thin film on a semiconductor substrate in an atmosphere containing a reducing element; and annealing the semiconductor substrate and the thin film after depositing the thin film. manufacturing method. (2) The method for manufacturing a semiconductor device according to claim 1, wherein the annealing is performed by infrared radiation. (3) The method for manufacturing a semiconductor device according to claim 1, wherein the annealing is performed by high-energy beam irradiation. (4) The method for manufacturing a semiconductor device according to claim 3, wherein the high-energy beam is an ultraviolet light, a laser beam, an ion beam, or an electron beam.