Method of etching semiconductor device using neutral beam and apparatus for etching the same

Abstract

A method and an apparatus for etching a semiconductor device which can perform an etching process without causing electrical and physical damages using a neutral beam generated by a simple apparatus. In the method, ions of an ion beam having a predetermined polarity are extracted from an ion source and accelerated. An accelerated ion beam is reflected by a reflector and neutralized. A substrate to be etched positioned in the path of the neutral beam in order to etch a special material layer on the substrate with the neutral beam. The gradient of the reflector is adjusted to control an angle of incidence of the ion beam incident on the reflector, and a voltage is applied to the reflector to control the path of an incident ion beam.

Description

BACKGROUND OF THE INVENTION[0001] 1. Field of the Invention[0002] The present invention relates to a method of etching a semiconductor device and an apparatus for etching the same, and more particularly, to a method of etching a nanoscale semiconductor device and an apparatus for etching the same without damage by using a neutral beam.[0003] 2. Description of the Related Art[0004] As an increase in the integration density of semiconductor devices has been required, the design rule of integrated semiconductor circuits has been reduced. Thus, a critical dimension of 0.25 .mu.m or less is needed. Ion enhanced etching tools, such as a high density plasma etcher and a reactive ion etcher are mainly used as etching tools for realizing nanoscale semiconductor devices. In such case, high density ions having energies of a few hundred eV bombard a semiconductor substrate or a specific material layer on the semiconductor substrate for anisotropic etching. The bombardment of such ions causes ph...

AI Technical Summary

Benefits of technology

[0009] To solve the above-described problems, it is a first object of the present invention to provide a method of etching a semiconductor device which can perform an etching process without causing electrical and physical damages by the use of a neutral beam generated by installing only a simple apparatus and an apparatus for etching the large area by using the neutral beams.

[0010] It is a second object of the present invention to provide a damage-free method of etching a semiconductor device that can adjust the direction of a neutral beam to improve anisotropic etching by using only a simple apparatus and an apparatus for etching the large area.

[0014] According to the present invention, a reflector for reflecting an ion beam at a predetermined angle of incidence is included between an ion source generating an ion beam and a stage in which a substrate to be etched is installed. Thus, a neutral beam can be obtained by a simple method. An etching process can be easily performed for a nanoscale semiconductor device without causing electrical and physical damages to a substrate to be etched using the neutral beam, and scalability is easy.

[0016] Further, only ions having a predetermined direction are extracted to drastically reduce contamination generated due to the bombardment of unnecessary ions on the inner walls of a chamber.

Problems solved by technology

The bombardment of such ions causes physical and electrical damages to the semiconductor substrate or the specific material layer.

Dangling bonds may result in electrical damage as well as physical damage.

As electrical damage, there is gate dielectric charge-up or polysilicon notching due to photoresist charging.

Besides this physical and electrical damages, there is also possible contamination by materials of a chamber or the contamination of a surface layer by a reactive gas such as the generation of C-F polymers caused by the use of a CF-based gas.

Physical and electrical damages due to the bombardment of ions reduces the reliability of nanoscale semiconductor devices and productivity.

However, scalability is difficult in that it is difficult to perform anisotropic etching on micro-devices, and etch rate is low.

In the silicon etching technique by Takashi Yunogami, scalability is easy, but it is difficult to adjust the direction of the neutral beam and contamination possibility is high when extracting an ion beam.

In the etching technique by M. J. Goeckner, scalability is possible and a high neutral beam flux can be obtained, but the direction of the neutral beam is not clear due to ion-electron recombination, ions are mixed, and contamination possibility is high when extracting ions.

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