JPS6372128A - Thin film manufacturing device - Google Patents

Abstract

PURPOSE:To enable film thickness to be controlled, by disposing a device for measuring film thickness of a semiconductor thin film by the use of exo- electrons in a reaction tube while measuring the film thickness in process of forming the thin film. CONSTITUTION:A sample 7 is disposed on a sample holder 6 inside a quartz reaction core tube 2 surrounded with an electric furnace heater part 1. A detector 3 and an electron calculator 4 are disposed at the downstream part where a carrier gas 5 flows. The sample holder 6 can be moved forward and backward inside the quartz reaction-core tube. An oxidizing operation for the sample is performed while the sample is being mounted on a sample holder. After the oxidation is promoted to some degree, no oxgenous atmosphere is changed and the sample can be moved near the detector so as to be measured. After measurement of the film thickness, the sample can be returned under the oxygenous atmosphere. In this case, the detector 3 can be made to be two meters or more distant from the atmospheric position of the sample.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thin film manufacturing apparatus having a mechanism capable of measuring the thickness of a semiconductor or insulator thin film grown or attached on a substrate during the manufacturing process.

BACKGROUND OF THE INVENTION An example of thin film growth is growth in a heated (500 DEG -1200 DEG C.) furnace, usually in an oxidizing gas and carrier gas atmosphere.

To measure the film thickness during the growth process under normal pressure, if the film thickness is 500A or more, it is possible to visually measure the film thickness using the interference color of white light reflected from the boundary surface of the grown film. can.

However, this method is not suitable for use as control data for the growth of thin films, such as ultra-thin films of less than 500A, grown on a substrate.

Moreover, in order to measure a thin film thickness, it is not possible to take samples out sequentially during the film growth process.

In order to obtain a film of uniform quality and to control the film thickness, the atmosphere in which the film is grown cannot be changed even slightly. Generally, to measure the thickness of a film, a monitoring sample or a detector is taken out of the apparatus during the film forming process, observed with a film thickness measuring device, and the currently grown film thickness is measured.

Problems to be Solved by the Invention However, with this method, it is difficult to observe a thin film with a thickness of 500 Å or less.

The present invention aims to solve these problems, and controls the film thickness while observing the film thickness in the process of forming a thin film.

Means for Solving the Problems The present invention is a thin film manufacturing apparatus having a structure in which a semiconductor thin film measuring device using exoelectrons is set inside a reaction tube to enable film thickness measurement during the growth process.

According to the present invention, a film thickness measurement device using exoelectrons is installed at the rear end of the thin film forming reaction tube, and the sample in the film formation process is moved to the rear end, thereby making it possible to easily measure the thickness. .

Examples Generally, the surface of a solid, specifically a metal surface or a semiconductor surface, is exposed to electromagnetic waves such as ultraviolet rays, Metal surface or semiconductor surface electrons excited by electromagnetic waves or the like are emitted from the solid surface.

These are exoelectrons, and changes in the state of the surface can be observed by measuring this current value.

Exoelectrons are electrons that are unsteadily emitted from a solid by a mechanism different from normal thermionic emission or photoelectron emission, and are emitted electrons that are particularly dependent on structural changes in the solid.

The present invention makes use of this phenomenon to observe the thickness of the formed thin film without affecting the atmosphere in which the thin film is formed. Generally, semiconductor thin films are produced in an electric diffusion furnace, especially in the case of oxide thin films. In particular, when forming a thin film of 500A or less, a complicated mechanism is required to control the carrier gas composition and temperature, so it is desirable to measure the film thickness during the thin film growth process. An overview of the configuration is shown. That is, the sample 7 is placed on the sample holder 6 inside the quartz furnace core tube 2 enclosed in the electric furnace heater section 1 . A detector 3 and an electronic counting device 4 are set downstream through which the carrier gas 5 flows. Note that the sample holder 6 can be moved back and forth within the quartz furnace core tube. According to the present invention, the sample is subjected to the oxidation action while it is placed on the sample holder. After oxidation has progressed to a certain extent, the sample can be moved close to the detector and measured without changing the oxidation snow surroundings.

Once the film thickness has been observed, the atmosphere can be returned to the oxidizing atmosphere. In this case, the detector 3 can be separated from the sample atmosphere by 2 m or more, so the sample atmosphere is
It is possible to avoid radiant heat even at temperatures close to 000°C, and it is necessary to consider the constituent material of the detector 3 to create a mechanism that can withstand heat of 500 to 800°C. However, since the basics of the detector are only an ultraviolet light source and an electron collection electrode material, it is possible to install it near high temperatures. By moving the sample closer to the detector, measurements can be made without moving other mechanisms in the oxidation furnace or changing the atmosphere.

Figure 2 shows the situation during observation. Here, measurements are made possible by moving the sample holder.

Furthermore, depending on the measurement results, it is also possible to control the oxide film thickness by repeatedly moving the holder.

FIG. 3 shows the results of measuring the thickness of a silicon oxide film using the mechanism of the present invention.

Here, the results of measuring the oxidation time and amount of exoelectrons during the process of forming an oxide film are shown.

However, temperature correction due to sample removal shall be ignored.

FIG. 4 shows an example of observation of the exoelectron flow rate with respect to changes in a metal surface (aluminum) and a semiconductor (silicon) oxide thin film.

By applying this result, the thickness of the oxide thin film can be easily observed electrically.

Effects of the Invention According to the present invention, it is possible to accurately observe a semiconductor oxide film grown on a semiconductor substrate while it is growing.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views of the thin film manufacturing apparatus of the present invention,
FIG. 3 is a characteristic diagram of the relationship between the silicon oxidation time and the amount of exoelectrons according to the example, and FIG. 4 is a characteristic diagram of the relationship between the thickness of the metal oxide film and the semiconductor oxide film and the amount of exoelectrons. 1... Electric furnace heater section, 2... Quartz furnace core tube, 3... Detector, 4... Electronic counting device, 5... ...Carrier gas, 6...Sample holder, 7...Sample. Name of agent: Patent attorney Toshio Nakao and 1 other person 5"-7
Figure 2 Figure 3 (Bone 2

Claims (1)

[Claims] A thin film manufacturing apparatus characterized in that a semiconductor thin film thickness measuring device using exoelectrons is set inside a reaction tube.