Etching apparatus for manufacturing semiconductor devices

Abstract

An etching apparatus for manufacturing semiconductor devices which reduces contamination of the processing surface of a wafer by transporting a plurality of wafers stacked in a cassette with their processing surfaces facing down from the cassette supply chamber to one or more process chambers where the etching operation is performed on each wafer, one at a time. The apparatus has a load lock chamber for transferring the wafers stacked in the cassette from the cassette supply chamber, which is maintained under atmospheric conditions, to the process chamber, which is maintained under a strong vacuum. The process chamber has a cathode to which a wafer is clamped by a wafer holder with its processing surface facing down; the process chamber may also have a removable lower cover for easy repair and cleaning. The apparatus may also have a wafer aligning chamber installed between the cassette supply chamber and the load lock chamber for simultaneously aligning all of the wafers n the cassette before they are transported to the load lock chamber. The wafer aligning chamber also has a cassette transport mechanism for transferring the cassette from a cassette supply table in the cassette supply chamber to an elevator installed in the load lock chamber.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to an etching apparatus for manufacturing semiconductor devices, and more particularly, to an etching apparatus which reduces contamination of the surface of wafers during the step of transporting wafers to a process chamber and the step of etching the wafer as well as reducing the time it takes to transport and etch the wafers.[0003] 2. Discussion of Related Art[0004] The manufacture of semiconductor devices involves many processes, including photolithography, etching, and thin film fabrication, which are repeatedly performed during the manufacturing process. The etching process is required to eliminate any unnecessary film on the wafer, and can be divided into wet-etching processes utilizing chemicals, and dry-etching processes utilizing plasma.[0005] FIGS. 1 and 2 schematically illustrate the structure of a conventional dry-etching apparatus. The conventional dry-etching apparatus has multiple process chambers 1...

AI Technical Summary

Benefits of technology

[0013] It is another aspect of the present invention to reduce the process time required to transport the wafers back and forth between the wafer supply mechanism and the process chamber where the wafer is etched, and the time required to align the flat edges of the wafers, thereby enhancing operational efficiency of the etching apparatus.

[0015] In a preferred embodiment, the process chamber encompasses a sealed volume and has a side opening in communication with the load lock chamber which opening is sealed by a door, and a removable lower cover for easy cleaning and repair. The process chamber also has a cathode installed in the top part inside the chamber body, onto which cathode the wafer is clamped with its processing surface facing down to minimize contamination of the surface of the wafer during transport to and from the process chamber and during etching. The process chamber has a wafer loading mechanism for receiving the wafer supplied to the process chamber from the load lock chamber, and for clamping the wafer against the cathode. Finally, the process chamber has a process gas supplying component installed in the bottom of the chamber body for supplying the process gas to the chamber for etching the downward-facing wafer processing surface.

Problems solved by technology

In the conventional apparatus, the wafers are transported and aligned individually which is slow and inefficient, resulting in decreased productivity.

Contamination of the surface of the wafer W causes failures in the etching process.

There is a high risk of contamination of the upward-facing processing surface of the wafers W from particles that become attached to the surface as the wafers W are transported from the wafer supplying part 2 through load lock chamber 9 to the process chamber 1 where they are etched.

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