KR19980043610A - Contact hole cleaning method of semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a contact hole of a semiconductor device. In order to prevent deformation of a contact hole sidewall and damage to a junction, damage to a junction is minimized by performing cleaning using argon (Ar) plasma in a high frequency sputtering apparatus. Therefore, the present invention relates to a method of cleaning a contact hole of a semiconductor device in which the layer covering is improved during subsequent metal deposition, so that the yield of the device is increased and the contact resistance between the metal layer and the junction is reduced, thereby improving the electrical characteristics of the device.

Description

Contact hole cleaning method of semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning contact holes in semiconductor devices, and more particularly, to a method for cleaning contact holes in semiconductor devices to prevent deformation of contact hole sidewalls and damage to junctions.

In general, a connection between a junction formed on a silicon substrate and a conductive layer or conductive layer in a semiconductor device manufacturing process is made through a contact hole. The contact hole is formed by patterning an insulating layer by a photo and etching process, and after the etching process, reaction by-products generated by the etching gas or etchant used in the etching process and various defects are formed on the silicon substrate. It exists. Therefore, after the contact hole is formed, a cleaning process for removing reaction by-products and defects existing on the silicon substrate should be performed. A method of cleaning a contact hole of a conventional semiconductor device will now be described with reference to FIGS. 1A and 1B.

Conventionally, as shown in FIG. 1A, the insulating layer 3 formed on the silicon substrate 1 is patterned to form a contact hole 4 to expose the junction 2, and then wet with a buffered oxide etchant (BOE) solution. Cleaning or plasma dry cleaning using a gas such as CF 4 / O 2 or NF 3 is performed to remove the reaction by-products 5 remaining on the exposed silicon substrate 1. However, when the wet cleaning is performed, the insulating film 3 exposed by the isotropic etching characteristic is lost, and thus the shape of the sidewall of the contact hole 4 is deformed as shown in FIG. 1A, and the dry cleaning is performed. Damage to the surface (part A) of the exposed junction portion 2 as shown in FIG. 1B is caused by the plasma ions. Therefore, due to the above problems, the layer covering of the metal in the contact hole 4 is poor or the contact resistance between the metal layer and the junction 2 is increased, thereby deteriorating the electrical characteristics of the device.

Accordingly, the present invention provides a method for cleaning a contact hole of a semiconductor device which can solve the above disadvantages by using a dry cleaning method that does not cause deformation of contact hole sidewalls due to loss of an insulating film, and minimizes damage to a junction. The purpose is.

According to an aspect of the present invention, a silicon substrate having a contact hole is loaded into a high frequency sputtering apparatus, and the surface of the silicon substrate is cleaned using argon (Ar) plasma, and the air is waited for a predetermined time from the step. The silicon substrate is unloaded to the outside of the high frequency sputtering apparatus after maintaining the state, and the cleaning process is performed at a temperature of 400 to 550 ° C. and 100 to 200 watts (W) to the high frequency sputtering equipment during the cleaning process. It is characterized in that the high frequency power is supplied.

1A and 1B are cross-sectional views of a device for explaining a contact hole cleaning method of a conventional semiconductor device.

2A and 2B are cross-sectional views of a device for explaining a contact hole cleaning method of a semiconductor device according to the present invention.

Explanation of symbols for main parts of drawings *

1 and 11: silicon substrates 2 and 12: junction

3 and 13: insulating film 4 and 14: contact hole

5 and 15: reaction byproducts

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

2A and 2B are cross-sectional views of a device for explaining a contact hole cleaning method of a semiconductor device according to the present invention, and FIG. 2A shows a junction portion 12 by patterning a first insulating film 13 formed on a silicon substrate 11. Is a cross-sectional view of the contact hole 14 formed so that the reaction hole 15 is exposed, and the reaction by-product 15 generated during the patterning of the insulating layer 13 remains on the silicon substrate 1.

2B shows that the reaction byproduct 15 is removed by dry cleaning using an argon (Ar) plasma after loading the silicon substrate 11 into a high frequency sputtering apparatus at a temperature of 400 to 550 ° C. As a cross-sectional view of the state, the high-frequency sputtering equipment is supplied with a low frequency RF power of about 100 to 200 watts (W) to minimize the damage of the junction 12, the junction 12 is damaged If so, the silicon substrate 11 is heated to a temperature of 400 to 500 ° C to enable recovery. After the cleaning is completed, the silicon substrate 11 is unloaded to the outside of the high frequency sputtering equipment after maintaining the standby state for 10 to 60 seconds under the same temperature atmosphere.

As described above, the present invention uses a dry cleaning method that does not cause deformation of the contact hole sidewall due to the loss of the insulating layer, thereby minimizing damage to the junction, thereby improving layer coverage during subsequent metal deposition. The yield is increased and the contact resistance between the metal layer and the junction is reduced, there is an excellent effect that can improve the electrical properties of the device.

Claims (5)

In the contact hole cleaning method of a semiconductor device, Cleaning the surface of the silicon substrate using an argon (Ar) plasma after loading the silicon substrate having the contact hole into the high frequency sputtering apparatus; And maintaining the standby state for a predetermined time from the step, and then unloading the silicon substrate to the outside of the high frequency sputtering equipment. The method of claim 1, The cleaning process is a contact hole cleaning method of a semiconductor device, characterized in that carried out at a temperature of 400 to 550 ℃. The method according to claim 1 or 2, The high frequency power of 100 to 200 watts (W) is supplied to the high frequency sputtering equipment during the cleaning process. The method according to claim 1 or 2, The silicon substrate is heated in a temperature of 400 to 500 ℃ during the cleaning process, the contact hole cleaning method of a semiconductor device. The method of claim 1, The standby state is maintained for 10 to 60 seconds, the contact hole cleaning method of a semiconductor device.