JPS6311672A - Formation of thin film - Google Patents

Abstract

PURPOSE:To obtain a fine thin film pattern of high purity and accuracy when an electron beam is projected in an atmosphere contg. a material to be deposited to deposit the material on a substrate, by carrying out Auger analysis during the deposition. CONSTITUTION:When a material such as W is deposited on a substrate 106, vapor of a compound contg. the material as a constituent element, e.g., WF6 102 is fed to the surface of the substrate 106 as an atmospheric gas. An electron beam 111 is then projected on the desired part of the substrate 106 to deposit the material. During the deposition, a formed thin film is analyzed by in-Situ observation with an Auger analyzer 112.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film forming method for forming a thin film pattern on a substrate.

[Conventional technology]

Conventionally, in order to form a thin film pattern on a substrate, a mask such as a resist is used, and a semiconductor thin film is generally formed on an insulating substrate by vapor deposition or the like.

[Problem that the invention seeks to solve]

The purpose of the present invention is to enable the formation of fine thin film patterns of high purity and precision using electron beams without the need for masks such as resists, and to enable surface analysis of thin films formed by electron beam deposition. 1 in 5
It is an object of the present invention to provide a method for forming a thin film using Auger analysis with observation.

[Means for solving problems]

The thin film forming method of the present invention supplies a gas containing at least the material to be deposited as a constituent element onto a substrate to be deposited,
The method is characterized in that the material is deposited on the substrate while a desired portion of the substrate is irradiated with an electron beam and the surface layer of the deposited thin film is analyzed by Auger analysis.

[Principle/effect]

Next, the principle of the present invention will be explained using FIGS. 3 and 4.

FIG. 3 is a diagram for explaining the principle of electron beam deposition. When the substrate 32 to be deposited is placed in an atmosphere of gas molecules 31 containing the material to be deposited, the gas molecules 31 are adsorbed to the surface of the substrate 32 to be deposited. 33 indicates the adsorbed molecules. When the electron beam 34 is irradiated onto the substrate 32, the adsorbed molecules 33 of the atmospheric gas in the irradiated area are converted into the deposition material elements 35 and volatile material molecules 36 contained in the atmospheric gas adsorbed molecules 33 due to the energy of the electron beam 34. Decomposed, the deposition material element 35 is deposited on the substrate surface. Meanwhile, volatile material molecules 36 are discharged. According to the above principle, the deposition material contained in the atmospheric gas can be directly deposited and patterned by electron beam irradiation onto the surface of the deposition target substrate 32.

FIG. 4 shows a measurement configuration diagram of Auger analysis. A sample 42 is set on a sample stage 41, and the voltage is 1 to 10 KV.
In Auger analysis, the surface of the sample 42 is analyzed by making an electron beam 43 incident on the sample 42 and capturing Auger electrons 44 emitted from the sample 42 with an Auger analyzer 45.
An electron beam is used as an external probe to excite the sample 42, and Auger electrons with an energy of 2,000 eV or less are used as a signal. As a result, elemental analysis of a thickness of 20 Å or less is possible.

The present invention applies the Auger surface analysis method shown in FIG. 4 to the surface analysis of thin films deposited by electron beam deposition, and the electron beam used for electron beam deposition and the electron beam used for Auger analysis are By making them identical, surface analysis of thin films deposited by electron beam deposition can be performed in situ 15.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an apparatus used in this embodiment. This device has an electron beam irradiation system 109. Sample chamber 107, Auger analyzer 112. and an atmospheric gas material storage chamber 101. In this example, tungsten (
ν) as a constituent element (% I
W was deposited on the Si substrate 106 by a focused electron beam using F, ) 102 as an atmospheric gas. WF, 102 was placed in the atmosphere gas material storage chamber 101, and the 6Si substrate 106 set on the sample stage 105 using the SL substrate 106 on which W was deposited as a sample was subjected to buffer art hydrofluoric acid treatment and the surface was cleaned.

The sample chamber 107 was evacuated to a high vacuum of approximately 10-i0 Torr or more. WF, 102, which is an atmospheric gas material, is a liquid in the atmosphere, but is easily gasified by applying a vacuum. The VF, 102, passes through the pipe 103 and is introduced into the sample chamber 107 with its flow rate controlled by the mass flow controller 104. w supplied to sample chamber 107
F, 102 is in contact with the substrate 205 which is the sample;
wF molecules are adsorbed onto 5. The pressure in the sample chamber 107 is I
It is approximately X 10-'Torr. On the other hand, the electron beam 111 emitted from the electron beam gun 110 is
By converging and irradiating a desired part on the Si substrate 106 at 08, the WF adsorbed on the surface of the Si substrate 106 is
, is decomposed. As a result of the decomposition, VF is separated into W and F, and W is deposited on the Si substrate 106. Since F is a volatile gas, it is emitted.

In this way, W is deposited on the Si substrate 106.

Figure 2 shows the electron beam irradiation time and tungsten (V)
, fluorine (F), silicon (Si) Auger signal (V
: 179eV, F: 647eV, Si: 92eV)
It shows the measurement results with strength. The W Auger signal intensity increases with the electron beam irradiation time and is saturated after about 10 minutes of irradiation time. This is because the escape depth of Auger electrons in W is small, on the order of several dozen. The SL signal intensity decreases with the electron beam irradiation time, but this is because the silicon substrate surface is covered with W. The 6F Auger signal intensity is constant with the electron beam irradiation time.

As described above, according to the present invention, when irradiating an electron beam onto a substrate in a gas atmosphere containing a material to be deposited and depositing a deposition material contained in the atmospheric gas onto the substrate, in 5 itu Since it is possible to perform Auger analysis and surface analysis of the deposited thin film, it is possible to form a highly pure and highly accurate thin film.

In this example, VFs containing W is used as a deposition material.
was used as the atmospheric gas, but other raw materials were vcQ, wcΩ5. W can be deposited by using νBr, etc. Also, Mo(Cs)I containing Mo as a constituent element,
) 2, Mo (c,
M using Hs )2.

is deposited, Al2(CI+3) is used to deposit AQ, and Cr(Cs Ha )z is used to deposit Cr. Furthermore, Mo can be deposited using MoCQ, Moar5, or the like. Similarly, TaCf1. , Ta
Br5 etc. for Ta, TiI, etc. for Ti, Zr1
．． Zr can be deposited by An, Mo, w mentioned above,
Ti and the like can be used for wiring, gate electrodes, etc. in ICs and LSIs.

Furthermore, the thin film materials that can be deposited by the method of the present invention are not limited to metals. For example, if SiH4 gas is used as a raw material, a Si film can be deposited. On the other hand, if BCQ or BBr is used, B can be deposited, and if POCQ3 is used, P can be deposited, and B or P can be doped into the substrate. Further, by adjusting the flow rate ratio and pressure on the substrate, a Si film doped with B or P can be formed on the 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, by simultaneously supplying TiCQ4 gas and N2 gas onto the substrate surface and irradiating it with an electron beam, TiN
can be deposited. I Ti1. and Nzwri(N(czl
z]* can also form TiN. Sueda 5i (OCzHs
)4, Si0□ can be changed to Ta (OCi Hs )
If s is used, Ta2O can be formed.

Further, when the BCl21 r BBr and the metal forming material are used simultaneously, a poride film can be formed.

〔Effect of the invention〕

As explained above, according to the present invention, a thin film pattern can be easily formed by electron beam deposition, and the surface analysis of the formed thin film can be performed in 5 itU by Auger analysis, resulting in high purity and high precision. This has the effect that a fine thin film pattern can be easily obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an electron beam deposition apparatus for explaining one embodiment of the present invention, and FIG. 2 is a WF. The difference in electron beam irradiation time when using a source,
F, Si element in 5itu Iij! FIG. 3 is a diagram illustrating the principle of electron beam deposition, and FIG. 4 is a diagram illustrating the measurement configuration of Auger analysis. 31... Gas molecules, 32, 42, 106... Substrate (
sample), 33...adsorbed molecules, 34,43,111...
・Electron beam, 35...Deposition material element, 36
...Volatile material molecules, 45,112...Auger analyzer, 102...wF.

Claims (1)

[Claims] (1) Supplying a gas containing at least the material to be deposited as a constituent element onto the substrate to be deposited, irradiating a desired portion of the substrate with an electron beam, and analyzing the surface layer of the deposited thin film by Auger analysis, A method for forming a thin film, comprising depositing the material on a substrate.