JPS60216549A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To treat a semiconductor substrate without being exposed to the outside air by housing the semiconductor substrate in the same reaction chamber, introducing different reaction gases in succession and projecting beams imparting corresponding energy. CONSTITUTION:A reaction chamber 2 is evacuated 3 and an Si substrate 1 is heated 4 at approximately 250 deg.C, and SiH4 6, NO2 7 and N2 8 at predetermined flow rates are fed to keep the inside of the reaction chamber at approximately 10Torr. when the substrate 1 is irradiated and scanned by ArF laser beams 9, an SiO2 film 12 is formed on the whole surface. When the introduction of the gases is stopped, the reaction chamber is evacuated and CFCl2 is introduced and only a prescribed region 15 is irradiated by CO2 laser beams 14, the SiO2 film 12 is removed. According to the constitution, two processing processes can be executed in the same reaction chamber by utilizing an optical CVD method and other photochemical reactions, the substrate is not contaminated by the outside air, and the substrate need not be heated at a high temperature by utilizing the photochemical reactions and is not damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for manufacturing a semiconductor device by performing a series of semiconductor processing steps such as thin film growth, impurity diffusion, and etching on a semiconductor substrate.

[Prior art and its problems]

In order to manufacture semiconductor devices, semiconductor substrates are processed through various processes such as adhesion of impurities to the surface of the semiconductor substrate, diffusion into the substrate, formation of an oxide film, nitride film, or metal film, and selective etching using a photo process. processing is applied. However, when the semiconductor substrate is exposed to high temperatures in these steps, there is a problem of generation of crystal defects due to thermal deformation or thermal stress of the substrate. For example, with the increase in the degree of integration of semiconductor integrated circuits, there is a growing demand for finer junction or interconnect designs and higher accuracy in impurity concentration control. Methods such as etching using an extracted ion beam, vapor phase growth, and compound generation, and so-called dry processes such as ion implantation have come to be employed. However, these methods have the problem of causing damage to the crystal.

Furthermore, in the middle of these series of steps, the semiconductor substrate is taken out from one processing device and placed in another, so the semiconductor substrate inevitably comes into contact with the outside environment, and during that time the substrate is Contamination may occur. Connecting two devices and moving the substrate so as not to expose it to the outside air increases the area occupied by the equipment and increases the cost of the equipment.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device that eliminates the above-mentioned drawbacks and does not expose a semiconductor substrate to the outside air during successive semiconductor processing steps.

[Key points of the invention]

According to the present invention, by accommodating at least two consecutive semiconductor processing steps on a semiconductor substrate in the same reaction chamber, sequentially introducing different reaction gases, and irradiating each with light giving corresponding reaction energy. By doing so, the above purpose is achieved.

[Embodiments of the invention]

Hereinafter, referring to FIG. 1 showing an apparatus for implementing the present invention and FIG. 2 showing an enlarged view of a silicon substrate, the process of forming a silicon oxide film on a silicon substrate using a photochemical reaction, and then An embodiment comprising a step of removing a portion of the silicon oxide film to form a mask pattern for introducing impurities will be described.

The silicon substrate 1 is placed on the bottom of the reaction chamber 2, and the reaction chamber is evacuated to a vacuum using the vacuum pump 3, and then the substrate 1 is heated to about 250° C. by the heater 4, and the mass flow meter 5
8iH4 gas from cylinder 6 by controlling the flow rate by
d/min, 800-Le' of N20 gas from cylinder 7.
mln, N2 gas from cylinder 8 as carrier gas 6
5 sd/min and maintain the pressure at around 1 OTorr. There, the 193OA oscillation light 9 of the rF excimer laser is sent to the mirror 10. By irradiating directly above the substrate 1 through the lens 11 and scanning, 8iH4+ 2N20-8iOz
A reaction of + Hz + 2Nz occurs, and the entire surface appears as shown in Figure 2.
An oxide layer as shown in 1) is produced. Next, cylinder 6°7
．． After stopping the introduction of gas from 8 and evacuating the inside of the reaction chamber 2, cpczz gas is introduced from the pump 13, and the mirror 10 is rotated to transmit the oscillation light 14 of the COz laser having a wavelength of 1000 μm to the substrate 1 in FIG. Only the area 15 indicated by the dotted line in (a) is irradiated. From this K, C'l'C12+ 8i02-
The reaction of SmuFzC1z + CO2 occurs, and 81F2
810z jII of the irradiated part due to scattering of 012! 12
is removed as shown in FIG. 2(b) K. As a result, the conventional method involves 8 steps of thermal oxidation, resist coating, exposure through a photomask,
What required each step of resist removal can be replaced by successive steps within the same reaction chamber.

〔Effect of the invention〕

The present invention provides at least two consecutive processing steps for a semiconductor substrate, each of which is performed in the same reaction chamber by an optical CVD method or other method that utilizes a photochemical reaction.
This prevents the semiconductor substrate from coming into contact with external ambient air and becoming contaminated during successive processes. By expanding the present invention, it becomes possible to perform all steps of semiconductor device manufacturing by light irradiation in the same reaction chamber. Furthermore, since the use of photochemical reactions does not require heating the semiconductor substrate to a high temperature and there is no risk of damage to the substrate, it can be extremely effectively applied to improving the characteristics of semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view sequentially showing steps of forming a silicon oxide film pattern in an embodiment of the present invention. 1...Silicon substrate, 2--Reaction chamber, 6-8iH4 cylinder, 7 ・N, 0 cylinder, 8 ・N, cylinder, 9...
・Human rF excimer laser light, 12 ・Stow film, 13
- CFC1x cylinder, 14-Co laser beam.

Claims (1)

[Claims] l) A method in which at least two consecutive semiconductor processing steps for a semiconductor substrate are carried out by accommodating the semiconductor substrate in the same reaction chamber and sequentially introducing different reaction gases into the reaction chamber.