JPH01115120A - Formation of thin film - Google Patents

Abstract

PURPOSE:To simplify a process by changing a section, to which the ions of oxygen are implanted, into silicon oxide by implanting the ions onto an silicon substrate and conducting silicon epitaxy to the section, to which the ions are implanted, through silicon selective epitaxy. CONSTITUTION:A mask 12 composed of a resist, etc., is formed onto a substrate 11 through beams and an electron-beam exposure method. Ions are implanted to the silicon substrate 11 by oxygen ion beams 13, and an oxygen-ion implanting region 13 is shaped. An silicon oxide layer can be shaped selectively through oxygen-ion implantation by removing the mask 12. Accordingly, an silicon oxide layer 13 is formed selectively onto the silicon substrate 11 through the selective ion implantation of oxygen, and the selective epitaxy of silicon is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of forming a thin film by selective epitaxy of a silicon thin film using selective ion implantation.

(Prior Art) FIG. 2 shows a conventional silicon selective epitaxy process. In FIG. 2(1), a thermal oxide film 22 is formed on a substrate 21, and a mask 23 such as a resist is further formed.
is formed by light or electron beam exposure (Fig. 2 (1)
). Next, using the mask 23, the thermal oxide film 22 is etched by CF4 reactive ion etching (second
(21), and then the resist is removed by oxygen plasma ('Figure 2 (3)). In this manner, a thermal oxide film pattern is formed on the silicon substrate. Thereafter, silicon selective epitaxy is performed by gas reactive vapor phase growth using a dichlorosilane source, in which silicon grows only on the silicon, and silicon does not grow on the thermal oxide film.

(Problems to be Solved by the Invention) However, this conventional method has the disadvantage that the steps are complicated. An object of the present invention is to provide a method for forming a thin film by silicon selective epitaxy, which has a simplified process by selective ion implantation.

(Means for solving the problem) The present invention implants oxygen ions onto a silicon substrate, turns the ion-implanted area into silicon oxide, and performs silicon epitaxy only on the ion-implanted area by silicon selective epitaxy. This is a thin film forming method characterized by performing the following steps.

(Operation) The principle and operation of the present invention will be described. In the field of ion implantation, there is a technology for surface modification by implanting ions into a substrate. For example, by implanting oxygen ions into a silicon substrate, the surface of the substrate can be made into silicon oxide (SiOx). , where the value of X can be controlled by the amount of oxygen ion implantation. Furthermore, the depth of ion implantation can be controlled by the ion acceleration energy during ion implantation. In this way, silicon oxide can be formed on a silicon substrate by surface modification technology using ion implantation. A silicon oxide layer can be selectively formed on a silicon substrate by implanting oxygen ions into the silicon substrate. Therefore, by selectively implanting oxygen ions, it is possible to selectively form a silicon oxide layer on a silicon substrate and perform selective epitaxy of silicon.

(Example) Hereinafter, an example of the present invention will be described using FIG. 1. In FIG. 1 (1), a mask 12 such as a resist is formed on a substrate 11 by light or electron beam exposure (see FIG. Implantation is performed, here, the acceleration energy is 200 ke and the dose is 1 x 1018/
A cta2 oxygen ion beam was used. In this way,
An oxygen ion implantation region 13 is formed. (Figure 1 (21)
. Next, the mask 12 is removed (FIG. 1 +31), and in this way a silicon oxide layer is selectively formed by oxygen ion implantation. Next, selective epitaxy can be performed by gas-reactive vapor phase epitaxy using dichlorosilane so that silicon grows only in the region (silicon oxide) into which oxygen ions have been implanted (FIG. 1 (4)). In this example, an acceleration energy of 200 keV was used, but since selective epitaxy utilizes a difference in surface energy, ions may be implanted with an even lower energy. Also, the dose is 1 x 10
”/cta2 or more 1x1020/cta2 range is sufficient.

(Effects of the Invention) As explained above, according to the thin film forming method of the present invention, the process is simplified by implanting oxygen ions onto a silicon substrate to selectively form a silicon oxide layer and performing selective epitaxy. It is possible to form a thin silicon film.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view schematically showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a conventional silicon selective epitaxy method. 11.21: Si substrate, 12.23: Mask, 14.2
3: Si epitaxial thin film, 13: implantation region,

Claims (1)

[Claims] A process of selectively forming silicon oxide only in the ion-implanted areas by implanting oxygen ions onto a silicon substrate, and a process of performing silicon epitaxy only on the ion-implanted areas by epitaxial growth. A thin film forming method characterized by: