JPS5987821A - Oxidization - Google Patents

Abstract

PURPOSE:To form a high quality oxide film at low temperature by a method wherein a semiconductor substrate is placed in the atmosphere containing ozone and vapor and oxidized by heating. CONSTITUTION:Si wafers 3 are placed on a quartz jig 2 put in a quartz reaction tube 1 and the tube 1 is in a heated condition by the heater 4. Ozone is supplied from an ozone piping 8 and introduced through the water 6 heated to 90 deg.C by a heater 7 so that the gas containing vapor is supplied into the quartz tube 1 and the Si wafer 3 is oxidized. As the Si is oxidized in the atmosphere containing ozone and vapor, in order to form an SiO2 film of 1,000Angstrom thickness oxidization is performed at the temperature of 600 deg.C for 30min compared to the conventional dry oxidization method which needs 1,150 deg.C for 30min and conventional wet oxidization method which needs 800 deg.C for 30min. Thus oxidization of Si can be performed at low temperature.

Description

[Detailed description of the invention] The present invention relates to a method for oxidizing semiconductor materials.

Conventionally, semiconductor materials, especially Sl, have been oxidized using the so-called dry oxidation method, in which a device 31 is placed in an oxygen atmosphere and heated at a high temperature, or the so-called wet oxidation method, in which a device 81 is placed in an atmosphere containing water vapor and heated. method was used.

However, according to the above-mentioned prior art, there was a drawback that the heating temperature of 81 required a high temperature of 1000° C. or higher in the case of dry oxidation or 800° C. or higher even in the case of wet oxidation.

An object of the present invention is to improve the above-mentioned conventional techniques and provide a method for forming a high-quality oxide film at a low temperature on a semiconductor substrate.

The basic structure of the present invention for achieving the above object is that, in a semiconductor substrate oxidation method, a semiconductor substrate is placed in an atmosphere containing at least ozone and water vapor, and the substrate is heated to oxidize. Features.

Hereinafter, the present invention will be explained in detail with reference to Examples.

1 to 5 are schematic diagrams showing examples of the oxidation method according to the present invention. In FIG. 1, a Si wafer 3 is placed on a quartz jig 2 placed in a quartz reaction tube 1, heated by a heater 4, and ozone (03) is supplied into the quartz tube 1 from a pipe 8. The ozone is passed through water 6 heated to 90°C by a heater 7, and a gas containing water vapor is supplied.
13 is oxidized. Figures 2, 3, and 4 are similar in structure to Figure 1, with 5113.2 installed on quartz jigs 12, 22, and 32 in a quartz tube 11.21.31.
Pipe 1 which heats 3.53 with heaters 14, 24, and 34 and supplies ozone into the quartz tubes 11, 21, and 31.
8, 26.56, ozone is supplied, but the method of supplying water vapor is different. In FIG. 2, water 16 in a bubbler 15 heated by a heater 17 is bubbled with N supplied from an N2 gas supply pipe 19, and an atmosphere in which gas is bubbled is supplied into a quartz tube 11. In FIG. 3, a flame 27 is formed by burning hydrogen and ozone supplied from a hydrogen gas supply pipe 25 and an ozone supply pipe 26 to supply an atmosphere of water vapor and ozone. In FIG. 4, water vapor is supplied into the quartz tube 31 from the combustion gas 37 by supplying hydrogen and oxygen from a hydrogen gas supply pipe 34 and an oxygen gas supply pipe 35, and ozone is separately supplied from a pipe 36. Although the method shown in FIG. 5 is similar, 8143 on the quartz jig 42 installed in the quartz tube 41 is heated with the heater 47, oxygen gas is supplied from the oxygen gas pipe 49, and the bubbler heated with the heater 45 is heated. In this method, oxygen and water vapor are supplied into the quartz tube 41 through water 47 in the quartz tube 46, and the supplied oxygen and far ultraviolet rays from the far ultraviolet lamp 45 turn into ozone.

As mentioned above, Si is grown in an atmosphere containing ozone and water vapor.
To form a 1oo'oX Sin film by oxidizing the
Whereas the wet oxidation method required 30 minutes of oxidation treatment at 800°C, in this method 60 minutes at 600°C is sufficient. As described above, the oxidation method according to the present invention has the effect of being able to oxidize 81 at low temperatures.

[Brief explanation of drawings]

1 to 5 are schematic diagrams showing examples of the oxidation method according to the present invention. 1.11, 21, 31, 41...Quartz tube 2.1
2, 22, 32. 42...Quartz jig 3.13.
23,33.43...Si wafer 4.14,
24, 34, 44, 7, 17.48...Heater 45...Far ultraviolet lamp 8.1B, 26.56...Ozone pipe 35
, 4.9...02 Gas e-pipe 5.15.1
6...Bubbler6.16.47...H,0 27,37...Flame and above Applicant Suwa Seikosha Co., Ltd. Agent Patent attorney Tsutomu Mogami 9> 1st Figure 3. Is 21 Aya (3rd, 3rd day 41 ε:ji 5IIJ 99-

Claims (2)

[Claims] (1) A method for oxidizing a semiconductor base, which comprises placing a semiconductor substrate in an atmosphere containing at least ozone and water vapor, and heating and oxidizing the substrate. (2) The oxidation method according to claim 1, characterized by a semiconductor substrate.