JPS6242417A - Thin film forming method - Google Patents

Abstract

PURPOSE:To form high purity microscopic thin film pattern in a highly precise manner without using a mask by a method wherein gas containing the material to be deposited is fed on the substrate on which said material is deposited, the substrate is cooled down to 10 deg.C or below, and an electron beam is made to irradiate on the desired part on the surface of the substrate. CONSTITUTION:When a cooled substrate 11 on which a material will be deposited is provided in the atmosphere of gas molecule 13 containing the material to be deposited, said gas molecule 13 is adsorbed on the surface of the substrate 11 whereon a material is deposited. The quantity of adsorption molecule 12 depends on the temperature of the substrate, and the quantity of adsorption becomes larger as the temperature of the substrate goes down. When an electron beam 16 is made to irradiate on the substrate 11, the adsorption molecule 12 of the atmospheric gas on the part whereon the electron beam 16 is projected is decomposed into the deposition material element 14 to be contained in the atmospheric gas adsorption molecule 12 and a volatile material molecule 15 by the energy of the electron beam, and the deposition material element 14 is deposited on the substrate surface. On the other hand, the volatile material molecule 15 is exhausted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thin film forming method for depositing a deposition material onto a substrate.

[Conventional technology]

Conventionally, when forming no-no-turns on a substrate, the process shown in Fig. 4 (,
) to (e) and the steps shown in FIGS. 5(,) to (d) are performed. In FIG. 4, a pattern-forming material 42 is formed on a substrate 41 by vapor deposition or a dripping method (FIG. 4(a)). Furthermore, resist 43 is applied in the fourth step.
(FIG. 4(B)) Then, the resist 43 is patterned by light exposure or electron beam exposure (FIG. 4(C)). Then, using the pattern of the resist 43 as a mask, pattern transfer is performed to the pattern forming material 42 by chemical etching or dry etching (fourth step).
Figure (d)). Then, the resist 43 is peeled off (the fourth
Figure (e)). FIGS. 5(1) to 5(d) show the lift-off process. A resist 52 is coated on the substrate 51 (FIG. 5(a)), and then the resist 52 is subjected to nolining by light exposure or electron beam exposure (FIG. 5(b)).

Next, /4' turn material 53 is deposited (FIG. 5(C)),
By peeling off the resist 52, the base material 53 can be formed on the substrate 51 (FIG. 5(d)).
.

[Problem that the invention seeks to solve]

This conventional method has the disadvantage that the process for forming the pattern material on the substrate is extremely long.

An object of the present invention is to provide a thin film forming method using an electron beam that can form a fine thin film pattern with high precision and high purity without requiring a mask such as a resist.

[Means for solving problems]

In the present invention, a gas containing at least a material to be deposited as a constituent element is supplied onto a substrate to be deposited, and the substrate is heated at 10°C.
This method of forming a thin film is characterized in that the material is deposited on a substrate by cooling the substrate and irradiating a desired portion of the surface with an electron beam.

[Effect]

Next, the principle and operation of the present invention will be explained using FIG. 1. Gas molecules containing the material to be deposited 1
Is the target cooled in the atmosphere of 3? When the printed substrate 11 is installed, gas molecules 13 are adsorbed onto the surface of the printed substrate 11. 12 indicates the adsorbed gas molecules.

The amount of adsorption depends on the substrate temperature, and the lower the substrate temperature, the larger the amount of adsorption. When the electron beam 16 is irradiated onto the substrate 11, the adsorbed molecules 12 of the atmospheric gas in the irradiated area are changed to the atmospheric gas adsorbed molecules 1 due to the energy of the electron beam 16.
2 is decomposed into a deposition material element 14 and a volatile material molecule 15, and the deposition material element 14 is deposited on the substrate surface. Meanwhile, volatile material molecules 15 are discharged. According to the principle described above, the digital material contained in the atmospheric gas is directly deposited and patterned on the surface of the digital substrate 11 by electron beam irradiation.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram of the apparatus used in this embodiment. This apparatus is composed of an electron beam irradiation system 208, a sample chamber 206, and an atmospheric gas material storage chamber 201. In this example, tungsten hexafluoride W6 containing tungsten (W) as a constituent element is used as an atmospheric gas, and W is de-distilled onto a 5io2 or 81 substrate with a thickness of 0.5 m by focused electron beam irradiation. Ta. WF6202
is placed in the atmospheric gas material storage chamber 201, and an 8% 02 or SL substrate 205 with a thickness of 0.5 μm on which W is to be deposited is set on the sample stage 204 as a sample. The electron beam irradiation system 208 and the sample chamber 206 are evacuated to a high vacuum of IOTory or higher. Although wF'6, which is an atmospheric gas material, is a liquid in the atmosphere, it is easily gasified by applying a vacuum, passes through the pipe 203, and is irradiated onto the substrate 205 that is the sample. The pressure in the sample chamber 206 is approximately 5×10 Torr.

An electron beam 210 emitted from an electron beam 209 is converged by a converging lens 207 to a diameter of 0.5 μm 810□ or S
0.1 by irradiating a desired portion on the substrate 205.
The 5 μm 8102 or St base substrate 20 and the coating 202 are disassembled. As a result of the decomposition, WF 6202 is divided into W and F. W is deposited on a 0.5 μm SiO□ or Sl substrate 205. On the other hand, F is a volatile gas and is therefore emitted. In this way, W is deposited on the 5IO2 or Sl substrate 205 in a thickness of 0.5 m. Figure 3 shows the relationship between substrate temperature and deposition thickness. The accelerating voltage and dose of the electron beam were each 10 kV.

2 C/crr? Met. 25℃ as substrate temperature, -
600.

It was measured at three points at -110°C. As the substrate temperature decreases, the adsorption rate of W6 on the substrate surface increases, so the deposition film thickness increases. The deposition film thickness at a substrate temperature of -110°C is approximately 4 times the deposition film thickness at a substrate temperature of 25°C.
000 times. In this way, the υ deposition film thickness is controlled by the substrate temperature.

In this example, WF′ containing wl is used as a deposition material.
Although W was used as the atmospheric gas, W can also be deposited by using other materials such as WCT6, WCL5, WB r 5, etc. Moreover, MO containing Mo as a constituent element (C
, 5H6) 2. Az (c
H,)5, cr(c6H6) containing Cr as a constituent element
)2 and other organometallic compounds exhibit similar effects.

When Mo (C6H6) 2 is used, Mo is deposited,
When using At(CH3), At is deposited and cr(e
When using 6ri4)2, Cr is deposited. ManoMo
MO can be deposited using Cr5*MoBr5 or the like. Similarly, T with TaCr5, TaBr3, etc.
Zr can be deposited using a r Ti 14 or the like and TllZr process 4 or the like. At, Mo, W, Ti, etc. mentioned above are IC,
It can be used for wiring, r-) electrodes, etc. in LSI.

Furthermore, the film material that can be deposited by the method of the present invention is not limited to metals. For example, if 5IH4 gas is used as a raw material, an S1 film can be deposited. On the other hand, BC1, and B B r
5 can be used to deposit B, and POct can be used to deposit P, and B and P can be doped into the substrate. Furthermore, by adjusting the flow rate ratio and pressure on the substrate, B and P are doped and 9S
An i-film can be formed on a substrate. Furthermore, since B or P can be deposited or doped as described above, a pn junction can be formed on the surface of a semiconductor substrate such as Si or GaAs.

In addition, TiN
can be deposited. TlI4 and N2. Tit:N(C2H5
)2) 4 can also form TiN. Maku 5l (OC2H
5) If you use 4, it will be 5102. If T'5(OC2H6)5 is used, Ta205 can be formed.

What if the BC1, BBr5 and the metal forming material are used at the same time? A two-sided film can be formed.

〔Effect of the invention〕

As explained above, the present invention uses electron beams to irradiate the surface of a substrate cooled in an atmospheric gas containing a digital material. Notion materials can be precipitated, and the process is extremely simple compared to conventional methods.

In addition, although a focused beam was used in the above embodiment,
An unfocused quadruplet beam may also be used.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram explaining the principle and operation of the present invention, Fig. 2 is a configuration diagram of an apparatus used in an embodiment of the present invention, and Fig. 3 shows experimental data of the embodiment shown in Fig. 2. Figure 4 (a
) ~ (s) and Figures 5 (a) ~ (d) are diagrams for explaining the conventional method of forming a pattern on a Vi substrate, and are schematic cross sections showing the cross sections of the substrate in the main steps in 1. It is a diagram. 14... Due to electron beam irradiation, atmospheric gas molecules adsorbed on the substrate surface are decomposed and deposited? Material molecules, 15... Volatile snow molecules generated as a result of decomposition of atmospheric gas molecules adsorbed to the substrate surface by Kameko beam irradiation, 16... Electron beam, 201... Atmosphere Gas material storage chamber, 202... Atmosphere gas material including deposition material, 203... Piping connecting the atmosphere gas material storage chamber and sample chamber, 204... Sample stand,
205... Substrate to be deposited, 206... Sample chamber, 207... Electron beam converging lens, 208...
・Electron beam irradiation system, 209...1 child beam gun, 2
10...1 child beam. 16 Electron beam%1 Figure Substrate temperature (°C) Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A gas containing at least the material to be deposited as a constituent element is supplied onto the substrate to be deposited, the substrate is cooled to 10°C or less, and a desired portion of the surface is irradiated with an electron beam to deposit the material onto the substrate. A method for forming a thin film, characterized by depositing it on top.