KR960005575B1 - Method for forming a capacitor of semiconductor device - Google Patents

Abstract

forming a field oxide layer(22), gate oxide layer(23) and gate electrode(24) on a semiconductor substrate(21), a spacer oxide layer(26) on the sides of the gate electrode(24), a source/drain region(25) by ion implantation, and an insulating oxide layer(27) on the substrate; coating the insulating oxide layer(27) with dual-tone resist(28) and exposing and sequentially developing it to form a resist pattern; selectively etching the insulating oxide layer(27) by using the resist pattern as a mask, to expose the source/drain region(25); reexposing the dual-tone resist pattern(28) to be removed, being left only on uneven portion of the oxide layer and exposing the insulating oxide layer(27); etching the exposed insulating oxide layer(27) to expose the source/drain region(25), removing the remaining dual-tone resist(28), and deposing a conductive material(29) for storing charges and patterning it.

Description

Capacitor Formation Method of Semiconductor Device

1 is a structure diagram of a conventional semiconductor device capacitor.

2 is a process diagram of manufacturing a semiconductor device capacitor according to the present invention.

* Explanation of symbols for main parts of the drawings

11, 21: semiconductor substrate 12, 22: field oxide film

13, 23: gate oxide film 14, 25: gate electrode

15, 25: source / drain regions 16, 26: spacer oxide film

17, 27: insulating oxide film 19, 29: conductive material for charge preservation

28: dual-tone resist

The present invention relates to a method for forming a capacitor of a semiconductor device.

Capacitors in typical semiconductor devices require increased capacitance capacity despite their small area. In order to solve such conflicting problems, trench type and stacked type have been used to increase the maximum capacitor capacity.

Referring to FIG. 1, a semiconductor substrate, 12 is a field oxide film, 12 is a gate oxide film, 14 is a gate electrode, 15 is a source / drain region, 16 is a spacer oxide film, and FIG. Silver insulating oxide film, 19 represents a charge storage conductive material, respectively.

First, the field oxide film 12 is formed on the semiconductor substrate 11, the gate oxide film 13, the gate electrode 14, the spacer oxide film 16, the source and drain regions 15 are formed, and then the insulating oxide film is formed. (17) is deposited to etch the insulating oxide film 17 over the source and drain regions 15 to form a charge preservation conductive material 19.

The charge storage electrode formed by the conventional method has a problem in that the charge storage electrode is formed on a flat surface and hits the side toward the capacitance side when the area of the unit cell is reduced due to high integration.

The present invention devised to solve the above problems is to provide a method of forming a capacitor of a semiconductor device that can be applied to a high-density device in which the unit cell area is reduced.

In order to achieve the above object, the present invention provides a gate oxide film, a gate electrode, a spacer coral film formed on the sidewall of the gate electrode, a source / drain region by ion implantation, and an insulating oxide film after the field oxide film is formed on the semiconductor substrate. After the first step of depositing, after the first step to apply a dual-tone resist (dual-tone resist) to expose the ultraviolet rays of the broadband to develop and then to open the insulating oxide film on the source / drain region by etching (open) A third step of etching the insulating oxide film opened using the dual resist developed after the second step as a mask, and after the third step, the dual resist is re-exposed to remove the dual resist except for the uneven portions of the oxide film Exposing the exposed oxide film after the fourth step of exposing the oxide film; And etching to expose the source / drain regions, and then removing the remaining dual resist and depositing and patterning a charge preservation conductive material.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to FIG. 2. In the drawings, 21 is a semiconductor substrate, 22 is a field oxide film, 23 is a gate oxide film, 24 is a gate electrode, and 25 is a source / drain. The region 26 is a spacer oxide film, 27 is an insulating oxide film, 28 is a dual resist, and 29 is a charge storage conductive material.

The field oxide film 22, the gate oxide film 23, the gate electrode 24, the spacer oxide film 26 formed on the sidewalls of the gate electrode 24, and ion implantation in the second (a) or semiconductor substrate 21 It is sectional drawing of the state which formed the source / drain area | region 25 and the insulating oxide film 27 was deposited.

FIG. 2 (b) is a cross-sectional view of the insulating oxide film 27 on the source / drain region 25 opened after the dual resist 28 is deposited and developed by exposing broadband ultraviolet rays.

FIG. 2 (c) is a cross-sectional view of the insulating oxide film 27 that is opened by using the developed dual resist 28 as a mask.

FIG. 2D is a cross-sectional view of a state in which the dual resist 28 is reexposed.

2E is a cross-sectional view of the insulating oxide film 27 exposed by removing unnecessary portions of the dual resist 28.

In FIG. 2 (f), the exposed insulating oxide layer 27 is dry etched to expose the source / drain regions 25 at predetermined portions, and then the photoresist layer 28 is removed and a charge preservation conductive material 29 is deposited. It is sectional drawing of the state formed in fixed size.

In this case, the insulating oxide layer 27 on the source / drain region 25 in which the insulating oxide layer 27 is etched at half thickness is completely etched to expose the source / drain region 25 in FIG. The remaining part remains half the thickness.

The present invention made as described above has the effect of increasing the capacitor of the semiconductor element by forming self-aligned irregularities on the insulating oxide film using a dual resistor.

Claims (2)

In the method of forming a capacitor of a semiconductor device, the field oxide film 22, the gate oxide film 23, the gate electrode 24, the spacer oxide film 26 formed on the sidewalls of the gate electrode 24, and the semiconductor substrate 21, A first step of forming the source / drain regions 25 by ion implantation and depositing the insulating oxide film 7, and after the first step, a dual-tone resist 28 is applied to expose broadband ultraviolet rays. And a second step of opening the insulating oxide film 27 on the source / drain region 25 by etching, and then using the dual resist 28 developed after the second step as a mask. After the third and third steps of etching the insulating oxide layer 27, the dual resist 28 is reexposed to remove the dual resist 28 except for the uneven portions of the oxide layer, thereby removing the insulating oxide layer 27. 4th Exposed After the fourth step, the exposed insulating oxide layer 27 is visualized to expose the source / drain regions 25, and then the remaining duality resist 28 is removed and the charge preservation conductive material 29 is removed. And a fifth step of depositing and patterning the capacitor. The method of claim 1, wherein the etching thickness of the insulating oxide layer (27) in the second step is 1/2 of the thickness of the insulating oxide layer (27).