KR19990051892A - Method of removing resist of semiconductor device - Google Patents

Abstract

The present invention relates to a resist removal method used as an ion implantation mask during a semiconductor device fabrication process, wherein a portion of the resist modified by an ion implantation process of a semiconductor device is removed by plasma etching using O ₂ + CF ₄ gas. and by removing the non-altered portion of the resist by plasma etching using O ₂ gas, and the resist residue by plasma etching using O ₂ gas Bring up the wafer on the chuck (chuck), generating a resist particles (particle) The present invention relates to a method for removing a resist of a semiconductor device which can be effectively removed without preventing contamination of wafers and contamination of tubes.

Description

Method of removing resist of semiconductor device

The present invention relates to a resist removal method used as an ion implantation mask during a semiconductor device fabrication process, wherein the resist portion deteriorated by the ion implantation process of the semiconductor device and the unmodified portion of the resist are separated into etching processes. The present invention relates to a method for removing a resist of a semiconductor device capable of removing the resist effectively without particle generation.

In general, resists are widely applied as ion implantation masks in the manufacturing process of semiconductor devices. After the ion implantation process using the resist as an ion implantation mask, the resist is removed by plasma etching using mainly O ₂ gas.

1 (a) to 1 (c) are cross-sectional views of a device for explaining a resist removal method of a conventional semiconductor device.

Referring to FIG. 1A, after the resist pattern 2 is formed on the semiconductor substrate 1, the resist pattern 2 is formed on the selected portion of the semiconductor substrate 1 by an ion implantation process using the resist pattern 2 as an ion implantation mask. The ion implantation region 3 is formed. The surface portion of the resist pattern 2 becomes the altered layer 2A by the ion implantation process, and the inside of the resist pattern 2 remains the non-denatured layer 2B.

Referring to FIG. 1B, in order to remove the resist pattern 2, a high temperature plasma etching process using an O ₂ gas is performed. A crack (2C) is formed in the altered layer 2A due to the high temperature. Is generated, and radicals enter the crack 2C portion.

Referring to FIG. 1 (c), during the high temperature O ₂ plasma etching process, as shown in FIG. 1 (b), not only cracks 2C are generated, but also the non-denatured layer 2B is formed by volatile components. The pressure is increased and eventually a phenomenon called pumping or burst occurs, causing the resist pattern 2 to be scattered in all directions. The non-oxidized surface denatured layer 2A scattered in all directions is reattached to the wafer surface and the tube, so that the phenomenon is not removed, and the reattached deformed layer remains particles that cause device defects. . This particle not only contaminates the wafer but also contaminates the tube, thereby reducing the reliability of the device.

Accordingly, the present invention removes the resist used as an ion implantation mask during the semiconductor device fabrication process by removing the resist portion and the unchanged portion of the resist by the separate etching process, thereby removing the resist particles. It is an object of the present invention to provide a method for removing a resist of a semiconductor device which can be effectively removed without generation.

In the resist removal method of the semiconductor device of the present invention for achieving the above object, an ion implantation process using a resist pattern as an ion implantation mask is performed, whereby a deteriorated layer is formed on the surface of the resist pattern, Remaining inside as an amorphous layer; Performing an O ₂ + CF ₄ plasma etching process at a low temperature to remove the altered layer of the resist pattern; Performing an O ₂ plasma etching process at a high temperature to remove the amorphous layer of the resist pattern; And continuing the O ₂ plasma etching process, removing the resist residue by floating the wafer in the middle of the tube using a pin or the like of the chuck.

1 (a) to 1 (c) are cross-sectional views of a device for explaining a resist removal method of a conventional semiconductor device.

2 (a) to 2 (d) are cross-sectional views of a device for explaining a resist removal method of a semiconductor device according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

1 and 11: semiconductor substrates 2 and 12: resist pattern

2A and 12A: altered layer 2B and 12B: unmodified layer

2C: crack 12C: resist residue

3 and 13: ion implantation zone

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

2 (a) to 2 (d) are cross-sectional views of a device for explaining a resist removing method of a semiconductor device according to an embodiment of the present invention.

Referring to FIG. 2A, after the resist pattern 12 is formed on the semiconductor substrate 11, the resist pattern 12 is formed on the selected portion of the semiconductor substrate 11 by an ion implantation process using the resist pattern 12 as an ion implantation mask. An ion implantation region 13 is formed. The surface portion of the resist pattern 12 becomes the altered layer 12A by the ion implantation process, and the inside of the resist pattern 12 remains the non-denatured layer 12B.

Referring to FIG. 2B, the deteriorated layer 12A of the resist pattern 12 is physically removed by a plasma etching process using O ₂ + CF ₄ gas. The O ₂ + CF ₄ plasma etching process is performed at a low temperature of about 120 ° C. or less to suppress generation of volatile components contained in the amorphous layer 12B.

Referring to FIG. 2C, the non-denatured layer 12B of the resist pattern 12 is chemically removed by a plasma etching process using an O ₂ gas. The O ₂ plasma etching process is performed at a high temperature of about 180 ° C. or more to minimize the resist residue 12C.

Referring to FIG. 2 (d), the O ₂ plasma etching process is continued, but the wafer is floated in the middle of the tube by using a pin of a chuck to completely remove the resist residue 12C. Since the wafer floats in the middle of the tube, a cooling effect of lowering the temperature of the wafer itself can be brought about, thereby preventing damage of the wafer due to heat during wafer unloading.

As described above, the present invention is to remove the resist used as the ion implantation mask in the semiconductor device manufacturing process by removing the portion of the resist modified by the ion implantation process of the semiconductor device and the unchanged portion of the resist by a separate etching process, Pumping or bursting can be prevented to reduce the particles of the resist, thereby preventing wafer contamination and tube contamination, thereby improving device reliability.

Claims (3)

Performing an ion implantation process using the resist pattern as an ion implantation mask, thereby forming a denatured layer on a surface portion of the resist pattern, and leaving the denatured layer inside the resist pattern; Performing an O ₂ + CF ₄ plasma etching process at a low temperature to remove the altered layer of the resist pattern; Performing an O ₂ plasma etching process at a high temperature to remove the amorphous layer of the resist pattern; And And continuing the O ₂ plasma etching process to remove the resist residues by floating the wafer in the middle of the tube by using the pins of the chuck. The method of claim 1, wherein the O ₂ + CF ₄ plasma etching process is performed at about 120 ° C. or less. The method of claim 1, wherein the O ₂ plasma etching process is performed at about 180 ° C. or more.