KR980012056A - Method for manufacturing capacitor of semiconductor memory device - Google Patents

Abstract

A method of manufacturing a capacitor for a semiconductor memory device is described. This is because the step of laminating the high-temperature oxide film and the polycrystalline silicon layer on the semiconductor substrate, the step of forming the photoresist pattern on the polycrystalline silicon layer, and the step of dry-etching the polycrystalline silicon layer using the photoresist pattern as the etching mask Removing the photoresist pattern by a dry etching method using ozone plasma, and removing the remaining high-temperature oxide film by dry etching using a mixed gas of hydrofluoric acid and steam And a process for producing the same. Therefore, according to the present invention, all of the etching processes for forming the storage electrode are performed by dry etching, thereby damaging the surface film quality of the storage electrode and preventing the additional cleaning process and the occurrence of the watermark thereon.

Description

Method for manufacturing capacitor of semiconductor memory device

The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing a capacitor of a semiconductor memory device capable of manufacturing a capacitor without damaging the film quality of a storage electrode.

In a typical capacitor manufacturing process during a manufacturing process of a semiconductor device, polysilicon for forming a storage electrode is dry-etched, and then a high-temperature oxide film, which is formed under the polysilicon and is used as an etch stop layer for the dry etching, (HTO) is removed using a wet solution. However, since such a wet etching process is a process using a chemical solution, there arises a problem that the surface film quality of the polycrystalline silicon for storage electrode formation is damaged. In order to cure such damage, a cleaning process (wet etching) is required one more time. This cleaning process provides a source of damage such as a water mark due to the nature of the polysilicon film.

Hereinafter, the problems that may arise from the above-described wet processes (the high-temperature film formation process and the cleaning process) are listed.

First, the polycrystalline silicon etching method for forming the storage electrode is a single wafer system, while the subsequent high temperature oxide film removing process is a wet etching method (one batch wafer system) Causing a loss of time.

Secondly, since a strong acid solution is used in the wet etching process, particles are generated during the process, and the surface film quality of the polycrystalline silicon for forming the storage electrode is damaged, so that a cleaning process is further required .

Third, no method has been developed to remove damage due to watermarks or the like, which may occur when the surface of the polycrystalline silicon for forming the storage electrode is treated with a chemical solution (enactment step).

It is an object of the present invention to provide a method of manufacturing a capacitor of a semiconductor memory device capable of solving the problems caused by the wet etching process as described above.

FIG. 1 is a cross-sectional view to illustrate general processes for forming a storage electrode of a capacitor.

FIG. 2 is a schematic view showing a cluster tool used to form a storage electrode of a capacitor according to the method of the present invention. FIG.

According to an aspect of the present invention, there is provided a method of manufacturing a capacitor of a semiconductor memory device, including: stacking a high-temperature oxide film and a polycrystalline silicon layer on a semiconductor substrate; Dry-etching the polycrystalline silicon layer on the polycrystalline silicon layer using a photoresist pattern as an etching mask to form a storage electrode made of the polycrystalline silicon layer; Removing the photoresist pattern by a dry etching method using ozone plasma; And a step of removing the remaining high-temperature oxide film by dry etching using a mixed gas of hydrofluoric acid and water vapor.

At this time, it is preferable to proceed the processes in a cluster tool.

Therefore, according to the present invention, all of the etching processes for forming the storage electrode are performed by dry etching, thereby damaging the surface film quality of the storage electrode and preventing the additional cleaning process and the occurrence of the watermark thereon.

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

FIG. 1 is a cross-sectional view for explaining a general process for forming a storage electrode of a capacitor. In FIG. 1, reference numeral 10 denotes a semiconductor substrate, reference numeral 12 denotes an interlayer insulating film, reference numeral 14 denotes a high- 16 "represents a spacer formed on the side wall of the contact window," 18 "represents a storage electrode, and" 20 "represents a photoresist pattern.

A typical capacitor manufacturing process includes forming a photoresist pattern 20 on a polycrystalline silicon layer for forming a storage electrode and etching the polycrystalline silicon layer using the photoresist pattern 20 as a mask, The photoresist pattern 20 and the high-temperature oxide film 14 are removed.

At this time, conventionally, the photoresist pattern removal and the high-temperature oxide film removal step are performed by a wet etching method. However, in the present invention, all of the removing steps are performed by a dry etching method.

The capacitor manufacturing process according to the present invention will be described in detail in the order of steps.

First, the polycrystalline silicon layer etching step (storage electrode 18 forming step)

A photoresist pattern 20 is formed on a polycrystalline silicon layer (which will be a storage electrode 18 by an etching process to be described later), and the polycrystalline silicon layer is patterned by using the photoresist pattern 20 as an etching mask, Etch by using dry etching method.

Second, the photoresist pattern removal step

The ozone (O ₃ ) plasma using a microwave is introduced into a chamber and the vacuum level, the reaction time and the flow rate ) To selectively etch only the photoresist pattern of the organic component.

Third, the high-temperature oxide film removing step

The high temperature oxide film is removed by using a gas mixture of anhydrous hydrogen fluorine and water vapor (H ₂ O). At this time, the selection ratio between the high-temperature oxide film and the polycrystalline silicon layer can be appropriately maintained by controlling the flow ratio, the vacuum level, and the temperature of the chamber of anhydrous hydrofluorine and steam.

All of the above dry etching processes are performed in a cluster tool, and Fig. 2 shows a cluster tool (3) used to form the storage electrode of the capacitor by the method according to the present invention As shown in the drawing, reference numeral 32 designates a load / unload unit, 34 designates a transport unit, 36 designates a dry etch unit, and 38 designates a dry cleaning unit .

The semiconductor substrate is loaded into the loader / unloader unit 32 and then transported to the dry etching unit 36 by the transport unit 34 to remove the etching process for forming the storage electrode, And then transported to the dry cleaning unit 38 by the transport unit 34 again for dry cleaning.

It is obvious that the present invention is not limited to the above embodiments and that many modifications are possible within the technical scope of the present invention by those skilled in the art.

According to the process for manufacturing a capacitor according to the present invention as described above, first, the same process (ie, dry etching) is continuously performed to minimize process stabilization and process time loss. Second, to minimize the damage of the marks and the like, and, third, to a process simplification can be expected to improve the processing quantity, the fourth, the photoresist after pattern removal is performed by dry etching process using a vacuum process, CO _x, gas of NO _x, etc. The removal of the storage electrode can be minimized.

Claims (2)

Stacking a high-temperature oxide film and a polycrystalline silicon layer on a semiconductor substrate; Forming a photoresist pattern on the polycrystalline silicon layer; Dry-etching the polycrystalline silicon layer using the photoresist pattern as an etching mask to form a storage electrode made of the polycrystalline silicon layer; Removing the photoresist pattern by a dry etching method using ozone plasma; And removing the remaining high-temperature oxide film by dry etching using a mixed gas of hydrofluoric acid and water vapor. The method of manufacturing a capacitor of a semiconductor memory device according to claim 1, 2. The method of claim 1, wherein the processes are performed in a cluster tool. ※ Note: It is disclosed by the contents of the first application.