KR960008904B1

KR960008904B1 - Forming method of silicon oxide film on the semiconductor substrate

Info

Publication number: KR960008904B1
Application number: KR1019920025029A
Authority: KR
Inventors: 유병곤; 유종선; 남기수
Original assignee: 조백제; 한국전기통신공사; 양승택; 재단법인한국전자통신연구소
Priority date: 1992-12-22
Filing date: 1992-12-22
Publication date: 1996-07-05
Also published as: KR940016583A

Abstract

The silicone dioxide film is prepared by introducing a mixed gas of 1-3% trichloroethane or trichloroethylene and oxygen or ozone into the oxidizing furnace for the lost 2-3mins. of oxidation process when the oxide film(2) with a 100nm thickness is formed on a silicone wafer(1) in the quartz tube at 900deg.C, and then accumulating chlorine atoms at the interface of silicone wafer(1) and silicone dioxide film(2). The obtained oxide film has no alkali metal like Na and pin-hole on silicone wafer.

Description

A method of forming a SiO 2 film on a semiconductor substrate.

제1a도와 b도는 종래의 SiO₂막의 제조공정과 소자 특성을 설명하기 위한 도면.1a and b are views for explaining the manufacturing process and device characteristics of a conventional SiO ₂ film.

제2도는 본 발명의 제조방법에 따라 SiO₂막을 제조하는 공정을 보인 도면.2 is a view showing a process for producing a SiO ₂ film according to the production method of the present invention.

본 발명은 반도체 기판상에 유전체막을 형성하는 방법에 관한 것으로서, 구체적으로는 염소를 기판과 SiO₂막의 계면에 주입되게 하는 유전체막 형성방법에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a dielectric film on a semiconductor substrate, and more particularly, to a method of forming a dielectric film in which chlorine is injected into an interface between a substrate and a SiO ₂ film.

종래의 유전체막 형성기술은 O₂가스만을 도입하여 실리콘을 산화시켜 유전체막을 형성하는 건식산화법과, 제1a도와 같이 게더링 효과(gettering effect)를 위하여 실리콘 기판(1)상에 SiO₂의 산화막(2)을 형성할때 계속하여 HCl 가스 등을 도입하여 산화막을 형성하는 방법이 이용되고 있다.Conventional dielectric film formation techniques include a dry oxidation method in which a dielectric film is formed by oxidizing silicon by introducing only O ₂ gas, and an oxide film of SiO ₂ on the silicon substrate 1 for a gettering effect as shown in FIG. ), A method of continuously introducing an HCl gas or the like to form an oxide film is used.

그런데, 이 종래의 기술에 의하면 HCl과 같은 가스를 실리콘 산화막(SiO₂)을 생성할때 처음부터 도입시키므로, SiO₂막중에 과도하게 염소(chlorine)가 도입되어 SiO₂막의 질이 좋지 않아 관홀(pin-hole) 등의 결함이 발생하기도 하고, 또한 나트륨(Na)등의 알칼리 이온이 충분히 제거되지 않고, 혹은 계면준위밀도 충분히 작게되지 않는 등의 문제점이 발생한다.By the way, according to the conventional techniques, because introducing a gas, such as HCl in the first place to produce a silicon oxide film (SiO _2), is excessively introduced into the chlorine (chlorine) to the SiO ₂ film does the quality SiO ₂ film good gwanhol ( Defects such as pin-holes may occur, and alkali ions such as sodium (Na) may not be sufficiently removed, or the interface level density may not be sufficiently small.

즉, 제1b도와 같이 전류가 활성영역에서 화살표 방향으로 흐를때 SiO₂막(2)내의 관홀(3)에 의해 전류의 흐름이 방해되기 때문에 소장의 특성이 저하되는 것이다.That is, as shown in FIG. 1B, when the current flows in the direction of the arrow in the active region, the flow of the current is disturbed by the tube hole 3 in the SiO ₂ film 2, so that the characteristics of the small intestine are deteriorated.

본 발명은 이러한 문제점을 해소하기 위해 제안된 것으로 관홀이 발생하지 않는 SiO₂막의 형성방법을 제공하는데 그 목적이 있다.The present invention has been proposed to solve this problem, and an object thereof is to provide a method for forming a SiO ₂ film in which no hole is generated.

이하, 첨부도면에 의거하여 본 발명의 실시예를 상세히 설명한다.Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

제2도와 같이 실리콘 웨이퍼(Si-wafer)(1)을 석영관 내에 넣어 산화 온도 900℃에서 가열함과 동시에 O₂가스를 도입하여 100nm 정도 두께의 산화막(2)을 형성할때, 산화 과정의 마지막 2~3분간 만에만 O₂가스에 대한 분율 1~3%정도의 TCA(trichloroethane; C₂H₃Cl₃)를 석영관 내에 도입하면 SiO₂/Si의 계면(4)에 염소가 도입되어 실리콘 웨이퍼 표면에 Na 등의 알카리 금속의 혼입과 핀홀(pin-hole)등이 없고 계면준위밀도가 충분히 작게 되는 SiO₂막(2)이 된다.As shown in FIG. 2, when the silicon wafer (Si-wafer) 1 is placed in a quartz tube and heated at an oxidation temperature of 900 ° C, an O ₂ gas is introduced to form an oxide film 2 having a thickness of about 100 nm. When only TCA (trichloroethane; C ₂ H ₃ Cl ₃ ) with a fraction of 1 to 3% of O ₂ gas is introduced into the quartz tube for the last 2 to 3 minutes, chlorine is introduced into the SiO ₂ / Si interface (4). It becomes the SiO2 film _{2 in} which alkali metal, such as Na, and pin-holes do not exist in the silicon wafer surface, and interface density is made small enough.

이렇게 생성된 SiO₂막(2)과 Si 기판(1) 계면에는 10¹²개/cm²정도의 Cl원자가 축적(pile-up)되어 계면준위밀도를 10¹⁰개/cm²이하로 감소시키는 작용을 한다.At the interface between the SiO ₂ film 2 and the Si substrate 1 thus formed, Cl atoms of about 10 ¹² atoms / cm ² are piled up to reduce the interface density to 10 ¹⁰ atoms / cm ² or less. do.

TCA 가스 대신에 HCl 가스 또는 TCE(trichloroethylene; C₂HCl₃)를 사용하여도 같은 효과를 나타내며 O₂가스대신에 O₃가스를 사용하여도 좋은 효과가 있다.Using HCl gas or TCE (trichloroethylene; C ₂ HCl ₃ ) instead of TCA gas has the same effect, and O ₃ gas can be used instead of O ₂ gas.

Claims

During the oxidation process in which the SiO ₂ film 2 is grown on the silicon substrate 1 as a dielectric film, trichloroethane (C ₂ H ₃ Cl ₃ ) having a fraction of 1 to 3% to O ₂ gas for the last 3 to 5 minutes. Alternatively, a mixed gas of trichlorethylene (C ₂ HCl ₃ ) and O ₂ gas or O ₃ gas is introduced into an oxidation furnace, and the SiO ₂ film 2 is grown to grow the silicon substrate 1 and the SiO ₂ film 2. A method of forming a SiO ₂ film on a semiconductor substrate, wherein Cl is accumulated at an interface therebetween.