KR100224651B1 - Method of manufacturing semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of separating devices between semiconductor devices, comprising: forming a pad oxide film on a silicon substrate and then trench etching the silicon substrate in a field region; Forming a repair oxide film for repairing the etch bond; Depositing a planarization film to fill trench portions; A heat treatment process for planarizing the planarization film; And a photolithography process of filling the planarization film only in the field region. Therefore, according to the method of the present invention, it is possible to greatly reduce the coating step due to the field region, and to repair the etching damage of the silicon substrate to improve the electrical characteristics of the leakage current, as well as to remove the phenomenon of the semiconductor device by removing the buzz beak phenomenon. There is a favorable advantage to high integration.

Description

Manufacturing Method of Semiconductor Device

1 to 3 are cross-sectional views of a process sequence showing a conventional LOCOS device isolation method.

4 to 8 are cross-sectional views of a process sequence showing a device isolation method of a preferred embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a device isolation device method using trench etching and possible refilling of a film.

Conventional device isolation techniques have mainly used a separation method using an oxidation process such as LOCOS (Local Oxidation of Sillcon) or SEPOX (Seletive Polysilicon Oxidatipn). Crystal defects caused by stress and redistribution of impurities implanted with ions have not been solved in principle.

In Figures 1 to 3 of the accompanying drawings, in the LOCOS device isolation method according to the conventional method, the cross-sectional view according to the manufacturing process is shown in sequence, and the conventional method will be described in detail with reference to the drawings. do.

First, the pad oxide film 11 and the nitride film 12 are sequentially stacked on the silicon substrate 10 (FIG. 1), and then the nitride film 12 on the field region is parametrically removed by a photolithography process. Let's do it.

At this time, a part of the pad oxide film 11 may be simultaneously etched due to the inconsistency of the etching degree. Subsequently, ion implantation 13 of channel blocking ions for blocking the inversion channel layer is carried out into the fill region (FIG. 2).

Then, the substrate silicon in the field region is oxidized to form a field oxide film 14 (FIG. 3).

The conventional LOCOS device isolation method described above exhibits various drawbacks as the semiconductor device develops to submicron device technology. The defects include crystal defects in the substrate silicon during the oxidation process due to pad oxide film and nitride film stress, and high temperature and long time. Oxidation changes the impurity distribution in the substrate silicon, weakening the electrical characteristics of the device, and in particular, the effective device area is reduced due to the bird's beak phenomenon in which the pad oxide film under the nitride film is oxidized to the active region. It is causing a big problem in high integration.

Accordingly, an object of the present invention is to improve a device isolation method capable of improving terminal coverage and electrical characteristics and increasing an effective device area, which is a conventional problem.

A preferred device isolation method for achieving the object of the present invention is to form a pad oxide film on a silicon substrate, and then trench etching the silicon substrate in the field region, forming a flat film to repair the etching defects, And depositing a planarization film to fill the trench, a heat treatment process to planarize the planarization film, and a photolithography process of filling the planarization film only in the field region.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

4 to 8 show a device separation method of the half body device according to the method of the present invention.

First, the pad oxide film 21 is grown on the silicon substrate 200, and the photoresist film 22 is applied to pattern the field region by a photographic process (FIG. 4). Subsequently, the silicon substrate 200 in the field region is trench-etched using the photoresist pattern 22 'as an etching mask (FIG. 5). In order to repair the etching damage caused to the silicon substrate 200 after the trench etching, a repair oxidation film 23 having a thickness of about 100 to 300 Å is formed by a dry oxidation method, and then BPSG (Borophosphorous) is used to fill the trench in the field region. A flattening film such as silica glass or PSG (Phosphoerons Sillcste Glass) is deposited to form a flattening film 24 by reflowing the flattening film through a heat treatment process (FIG. 6). Next, the planarization film 24 is etched back from the repair oxide film 23 on the active region with the planarization film 24 'having a thickness of about 1,000 ms as the etch end point, and then the field region is defined. A photoresist pattern 25 is formed, wherein the photoresist pattern is formed using an inverse pattern mask of a field region pattern mask used for trench etching the field region. Further, during the etch back process, the entire surface may be etched back using the silicon substrate 200 in the active region as an etching end point, and in this case, the device isolation process may be completed without the need for a subsequent process (FIG. 7). Subsequently, the planarization film 24 ′ and the repair oxide film 23 outside the field region are removed using the photosensitive pattern 25 as an etching mask to complete device isolation of the present invention (FIG. 8).

Therefore, according to the method of the present invention, it is possible to greatly reduce the coating barrier property due to the field region, and to repair the etch damage of the silicon substrate to improve the electrical characteristics such as leakage current and to remove the phenomenon of buzz beak semiconductor. There is an advantage to the high integration of the device.

Claims (5)

In the device-to-device separation method of a semiconductor device, after forming a pad oxide film on a silicon substrate, forming a repair oxide film for repairing etching defects and fixing a trench of the silicon substrate in a field region, and filling a trench portion And depositing a planarization film, a heat treatment process to planarize the planarization film, and a photolithography process of filling the planarization film only in the field region. The method of manufacturing a semiconductor device according to claim 1, wherein the repair oxide film is formed to a thickness of about 100 kPa to about 300 kPa by a dry oxidation process. The method of claim 1, wherein the planarization film is etched back using the planarization film having a thickness of about 1,000 micrometers as an etch end point on the repair oxide layer on the active region, and a process of forming a photoresist pattern defining a field region. A method of manufacturing a semiconductor device, characterized in that the planarization film is filled only in the field region through fixing to remove the uncovered planar film and the repair oxide film. The semiconductor device manufacturing method according to claim 1, wherein the planarization film is filled to only the field region by backing the planarization film to the entire surface with the silicon substrate in the active region as an etching end point. 4. The method of claim 3, wherein the photoresist pattern is formed using an inverse pattern mask of a field region pattern mark used for trench etching the field region.