KR0150103B1 - Fabrication method of electric charge storage electrode - Google Patents

Abstract

The present invention discloses a method of manufacturing a PSG film and a method of manufacturing a charge storage electrode of a semiconductor device using the same.

The present invention forms the first silicon oxide film in an undoped state by atmospheric pressure chemical vapor deposition, plasma chemical vapor deposition, or low pressure chemical vapor deposition to stabilize the film properties, and then to make the silicon oxide film with stable properties as a high dopant. In order to inject a large amount of phosphorus ions to produce a PSG film having a more stable film characteristics than the PSG film prepared by the conventional manufacturing method, it is possible to manufacture a cylindrical charge storage electrode having a desired shape by using such a PSG film. .

Description

Method for manufacturing phospho-silicate glass (PSG) film and method for manufacturing charge field electrode of semiconductor device using the same

1A to 1C are cross-sectional views of a device for explaining a method for manufacturing a charge storage electrode of a semiconductor device to which the PSG film production principle according to the present invention is applied.

2A to 2D are cross-sectional views of a device for explaining a method for manufacturing a charge storage electrode of a semiconductor device to which the PSG film production principle of the present invention is applied.

* Explanation of symbols for main parts of the drawings

1,11 wafer 2,12 silicon oxide film

2A, 12A: PSG film 13: junction

14 interlayer insulation film 15 polysilicon layer

16: Photoresist Pattern 17: Polysilicon spacer

The present invention relates to a method of manufacturing a phospho-silicate glass (PSG) film and a method of manufacturing a charge storage electrode of a semiconductor device using the same, and in particular, to improve the characteristics of the PSG film, and to use the improved PSG film The present invention relates to a method for manufacturing a PSG film and a method for manufacturing a charge storage electrode of a semiconductor device using the same.

Generally, PSG membranes are formed by Atomospheric Pressure Chemical Vapor Deposition (APCVD) using silicon ions, phosphorus ions, and oxidizers.

In recent years, as semiconductor devices have become highly integrated, the area occupied by capacitors is reduced, thereby reducing the capacitance. The minimum capacitance is required to operate the device, and one way to solve this problem is to study the maximization of the effective surface area of the charge storage electrode under a limited area. The PSG film is one of many films used to maximize the effective surface area of the charge storage electrode, and is particularly used to form a cylinder type charge storage electrode. PSG film, which is essential for the formation of the cylindrical charge storage electrode, is manufactured to have a high dopant due to its characteristics, which causes many problems in the process. That is, the photoresist used as an etching mask during the etching process for patterning the PSG film causes the photoresist to be lifted due to the deterioration of adhesiveness with the PSG film, and the charge storage electrode is cylinderd using the patterned PSG film. After forming the structure, there is a problem such as causing a bump phenomenon during the wet vision process for removing the patterned PSG film. As a result, there is a difficulty in forming a cylindrical charge storage electrode having a required shape.

Accordingly, the present invention improves the problem of the characteristics of the PSG film, the PSG film manufacturing method capable of forming a cylindrical charge storage electrode of the required shape using the improved PSG film and the manufacturing of the charge storage electrode of the semiconductor device using the same The purpose is to provide a method.

PSG film production method of the present invention for achieving this object is characterized in that after forming a silicon oxide film on the wafer, by implanting a phosphorous ion implantation process into the silicon oxide film to form a PSG film, such a PSG film In the method of manufacturing a charge storage electrode, an interlayer insulating film having an open junction is formed on a wafer, a polysilicon layer for a charge storage electrode is formed on the interlayer insulating film including the junction, and a silicon oxide film is formed on the polysilicon layer. Forming a PSG film by implanting phosphorus into the silicon oxide film by an ion implantation process, and forming a photoresist pattern on the PSG film by a lithography process using a mask for a charge storage electrode; The PSG film and the polysilicon layer having a pattern as an etch mask Removing the photoresist pattern after etching, and then forming a polysilicon spacer connected to the polysilicon layer by a polysilicon deposition process and a spacer etching process, and removing the PSG layer with a wet etching solution to remove the cylindrical charge storage electrode. It characterized in that the step consisting of manufacturing.

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

1A to 1C are cross-sectional views of elements for explaining the PSG film production method according to the present invention.

FIG. 1A shows a silicon oxide film 2 on a wafer 1 by atmospheric pressure chemical vapor deposition, plasma enhanced chemical vapor deposition (PECVD) or low pressure chemical vapor deposition (LPCVD). What is formed is shown.

FIG. 1B shows an ion implantation process using phosphorus 31P as source ions on the silicon oxide film 2, and as a result, the silicon oxide film 2 is PSG as shown in FIG. 1C. Film 2A.

In the above, the ion implantation process using phosphorus 31P as the source ions is performed so that the impurity implantation amount is in the range of 10 ¹³ to 10 ¹⁵ ions / cm ^{2 with} energy of 150 to 250 KeV.

In the above process, since the first silicon oxide film 2 is formed without impurities by the atmospheric pressure chemical vapor deposition method, the plasma chemical vapor deposition method or the low pressure chemical vapor deposition method, the film properties are stabilized, and then the silicon oxide film having the stable properties ( Since a large amount of phosphorus ions are injected in order to make the high dopant 2), the PSG film 2A having a more stable film property than the PSG film manufactured by the conventional manufacturing method can be manufactured.

2A to 2D are cross-sectional views of a device for explaining a method of manufacturing a charge storage electrode of a semiconductor device to which the PSG film production principle of the present invention is applied.

In FIG. 2A, an interlayer insulating film 14 having an open junction 13 is formed on a wafer 11, and a polysilicon layer 15 for a charge storage electrode is formed on an interlayer insulating film 14 including the junction 13. The silicon oxide film 12 is formed on the polysilicon layer 15 by atmospheric pressure chemical vapor deposition, plasma chemical vapor deposition, or low pressure chemical vapor deposition, and phosphorus 31P is formed on the silicon oxide film 12 as source ions. It is shown to carry out one ion implantation process.

In the above, the ion implantation process using phosphorus 31P as the source ions is performed so that the impurity implantation amount is in the range of 10 ¹³ to 10 ¹⁵ ions / cm ^{2 with} energy of 150 to 250 KeV.

2B shows that the silicon oxide film 12 becomes the PSG film 12A by the ion implantation process, and the photoresist pattern 16 is formed on the PSG film 12A by a lithography process using a mask for charge storage electrodes. Is shown.

2C shows that the PSG film 12A and the polysilicon layer 15 are etched using the photoresist pattern 16 as an etch mask, and then the photoresist pattern 16 is removed. Then, the polysilicon deposition process and the spacer etching process are performed. The polysilicon spacer 17 is shown in which the predetermined portion is connected to the etched polysilicon layer 15.

FIG. 2D shows the manufacture of the cylindrical charge storage electrode made of the polysilicon layer 15 and the polysilicon spacer 17 by removing the PSG film 12A with the wet etching solution.

As described above, since the first silicon oxide film is formed without impurities by the atmospheric pressure chemical vapor deposition method, the plasma chemical vapor deposition method, or the low pressure chemical vapor deposition method, the film characteristics are recognized and then the silicon oxide film with the stable characteristics is made to be a high dopant. Since a large amount of phosphorus ions are implanted, a PSG film having a stable film characteristic can be manufactured than a PSG film manufactured by a conventional manufacturing method, and a cylindrical charge storage electrode having a required shape can be manufactured by using the PSG film.

Claims (6)

A method of manufacturing a PSG film, comprising: forming a PSG film by forming a silicon oxide film on a wafer, and then injecting phosphorus into the silicon oxide film by an ion implantation process. The method of claim 1, wherein the silicon oxide film is formed of an impurity doped by any one of atmospheric pressure chemical vapor deposition, plasma chemical vapor deposition, and low pressure chemical vapor deposition. According to claim 1, wherein the ion implantation process PSG film production, characterized in that the impurity implantation is carried out in the range of 10 ¹³ to 10 ¹⁵ ions / cm ^{2 with} the energy of 150 to 250 KeV using the phosphorus as the source ion Way. A method for manufacturing a charge storage electrode of a semiconductor device, comprising: forming an interlayer insulating film having an open junction on a wafer; forming a polysilicon layer for a charge storage electrode on the interlayer insulating film including the junction; and forming a silicon on the polysilicon layer. Forming an oxide film, implanting a phosphorus into the silicon oxide film by an ion implantation process to form a PSG film, and forming a photoresist pattern on the PSG film by a lithography process using a mask for a charge storage electrode; And etching the PSG film and the polysilicon layer using the photoresist pattern as an etch mask, removing the photoresist pattern, and then polysilicon spacers connected to the polysilicon layer by a polysilicon deposition process and a spacer etching process. Forming and removing the PSG film with a wet etching solution. A charge storage electrode manufacturing method of the semiconductor device characterized in that comprising the steps of: preparing a cylindrical charge storage electrode. The method of claim 4, wherein the silicon oxide film is formed by an impurity doped by any one of atmospheric pressure chemical vapor deposition, plasma chemical vapor deposition, and low pressure chemical vapor deposition. The method of claim 4, wherein the ion implantation process using the phosphor as a source ion to produce a PSG film, characterized in that the impurity implantation is in the range of 10 ¹³ to 10 ¹⁵ ions / cm ^{2 with} an energy of 150 to 250 KeV Way.