JPS6127639A - Formation of oxide film pattern of semiconductor element - Google Patents

Abstract

PURPOSE:To enable to directly form an arbitrary oxide film pattern in high efficiency without using a photo mask and a photo resist by a method wherein an energy beam is irradiated on the semiconductor substrate applied with an oxidizing agent while the energy beam is scanned on the substrate and an oxidation is selectively performed on a part of the substrate according to an existence of the oxidation. CONSTITUTION:Oxidizing agent paste 33 is applied on the surface of a silicon substrate 31, the temperature of the surface is held being risen, an electron beam 34 is selectively irradiated, the oxidizing agent 33 at the irradiated part and the silicon substrate 31 are caused to react, and moreover, the unreacted oxidizing agent is removed to selectively obtain a silicon oxide film pattern 32 on the silicon substrate 31. This method can generate an oxidation reaction even when the interior of the device is held in an evacuated state, the efficiency of the electron beam 34 is good, and this method is specially effective in such the case that it is needed to obtain a fine pattern, because the beam becomes easier to narrow. Moreover, since the temperature of the surface of the substrate 31 is held being risen in some degree, the energy amount of the electron beam can be lessened as small as the component of the temperature being risen compared to that in the case the temperature of the surface is not being risen, thereby enabling to narrow the beam finer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an oxide film pattern of a semiconductor device.

In the conventional Ueno process for manufacturing semiconductor devices, as shown in FIG.
(hereinafter referred to as photoresist), placed the photomask 4 shown in Figure 1, exposed and developed, 1i11 [m
Obtain photoresist c; turn 5. Next, the photoresist pattern 76 is etched using an etching mask, and the silicon oxide film 2 is partially etched using, for example, a hydrofluoric acid-based etching solution, and the photoresist pattern 76 is removed. However, these methods have the following drawbacks. In other words, since a photoetching process is involved, the process becomes complicated and long, and pinholes caused by foreign matter occur during the photoetching process.

Defects are likely to occur due to handling errors, chipping (due to equipment), etc. Furthermore, the semiconductor surface is easily contaminated because it comes into contact with photoresist, developer, etching solution, etc., and the accuracy of mask alignment or etching target is affected. Microfabrication is difficult due to side etching of the material.

The present invention was invented in view of the above-mentioned drawbacks of the conventional method a, in which an energy beam is scanned and irradiated onto a semiconductor substrate coated with an oxidizing agent, and depending on whether or not the energy beam is irradiated, the This is a method for forming an oxide film pattern for a semiconductor element, characterized by selectively oxidizing a part of the surface of a semiconductor substrate to form an oxide film pattern.

The present invention is a method for forming an arbitrary pattern directly on a semiconductor substrate with high efficiency, without using a photomask or photoresist, and therefore without using any conventional photoetching process.

The present invention will be described below with reference to the drawings and an example in which an electron beam is used as the energy beam.

As shown in FIG. 2, the silicon substrate 11 is heated to a certain temperature in advance by an internal heater 12,
Electron beam 1 passing through blanking unit 13
4 is scanned using the scanning coil 15 and irradiated with energy almost perpendicularly to the surface of the silicon substrate 11 according to the intended pattern, thereby advancing the reaction of the patterned portion. , any oxide film pattern can be formed.

Furthermore, to explain a specific example, the method shown in FIG.
An oxidizing agent paste, for example, lead dioxide (Pb02) 33, is applied to the surface of the silicon substrate 31 to a thickness of several tens of microns, and
The temperature is raised to 250'C, the electron beam 34 is selectively irradiated, the oxidizing agent 33 in the irradiated area reacts with the silicon substrate 31 as (2PbO2+5i-2PbO+5IO2), and unreacted oxidizing agent is removed. Then, a silicon oxide film pattern 32 is selectively formed on a silicon substrate 31.

The method of this embodiment allows the oxidation reaction to occur even if the inside of the apparatus is kept in a vacuum, and the efficiency of the electron beam 34 is high.The method of this embodiment also makes it easier to narrow down the beam, so it is particularly useful when obtaining a fine pattern. It is valid.

Furthermore, since the surface of the substrate 31 has been heated to a certain extent, the energy amount of the electron beam can be reduced by that amount compared to the case where the temperature has not been increased. When used for LSI manufacturing, it has a great effect on the formation of fine patterns.

On the other hand, if the energy intensity is kept the same, the irradiation time can be significantly shortened, which is highly effective for mass production.

In this case, an impurity serving as a dopant, such as P)i3. It is also clear that if a small amount of P2O6 or the like is contained, impurity diffusion can be carried out locally. Furthermore, it is also possible to selectively etch the substrate by etching the selective oxide film.

As is clear from the above explanation, the present invention can significantly shorten the process compared to the conventional wafer process, does not require a photomask, and requires less chemical treatment due to the shortened process, resulting in contamination of the silicon substrate. This makes microfabrication easier, and furthermore, the entire silicon substrate can be
Since the temperature does not rise above 0°C, defects do not occur on the silicon substrate surface, and since the semiconductor substrate can be directly oxidized, a very flat oxide film pattern can be obtained.
It has advantages such as facilitating the formation of fine patterns in LSI manufacturing. Although this example shows the case where an electron beam is used, it is not limited to the electron beam. For example, it is possible to use a laser beam, positive beam, etc., which can be focused to locally give energy. can. The same effect can be achieved no matter which energy beam you use.

[Brief explanation of drawings]

Figures 1a to 1d are explanatory diagrams of the conventional photoetching process;
FIG. 2 is an enlarged view of the entrance of the electron beam irradiation diagram 2 used in the present invention. 31...7 recon board, 34...electron beam, 32...silicon oxide film pattern. ′
Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (3)

[Claims] (1) A step of applying an oxidizing agent to the surface of the semiconductor substrate, selectively irradiating the surface of the semiconductor substrate coated with the oxidizing agent with an energy beam from a substantially perpendicular direction, and depending on whether or not the energy beam is irradiated, 1. A method for forming an oxide film pattern for a semiconductor element, comprising a step of selectively oxidizing a part of the surface of a semiconductor substrate. (2) A method for forming an oxide film pattern on a semiconductor element according to claim 1, wherein the semiconductor substrate is heated to a predetermined temperature in advance during energy beam irradiation. (3) A method for forming an oxide film pattern on a semiconductor device according to claim 1, characterized in that an electron beam is used as the energy beam.