Plasma etching with microwave pre-excitation of the etching gas for mfr. of integrated semiconductor circuits - involves using excited, electrically neutral gas particles which are produced by plasma discharge and enter an etching reactor

摘要

Plasma etching involves preliminary excitation of the etching gas by means of microwave energy. Excited, electrically neutral particles of the etching gas are produced by means of plasma discharge. These particles enter into an etching reactor where a plasma etching process takes place with the use of high-frequency energy. The power of this energy is set at less than 400 W and, specifically, less than 150 W. Pref. the working pressure of the etching process is set at less than 13.3 Pa and, in particular, less than 1.3 PA. Such a process is employed for anisotropic etching by means of thin sidewall passivation and, in particular, less than 30 nm thick sidewall passivation. The method is also applicable for anisotropic ion-assisted chemical etching. USE/ADVANTAGE - Useful in the semiconductor circuit industry. It eliminates loading and microloading effects experienced with known methods employing high working pressure and power levels. It has also advantages over etching processes employing magnetic fields which may cause excessive ionisation.