Short‐gas‐residence‐time electron cyclotron resonance plasma etching

• Published in: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films Vol. 12; no. 4; pp. 1209 - 1215
• Main Authors: Tsujimoto, Kazunori, Kumihashi, Takao, Kofuji, Naoyuki, Tachi, Shin’ichi
• Format: Conference Proceeding Journal Article
• Language: English
• Published: 01-07-1994
• Subjects: PLASMA SOURCES; Si; SILICON; ETCHING; CONTAMINATION; ELECTRON CYCLOTRON−RESONANCE; GAS FLOW; SURFACE REACTIONS; ANISOTROPY
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.579297

This paper describes short‐gas‐residence‐time electron cyclotron resonance plasma etching for high etch rates, reduced contamination, and highly anisotropic etching. The new high‐gas‐flow‐rate (high‐flow) etching system is demonstrated with effective‐pumping rate of 2500 l/s. This method produces very high etch rate while maintaining high anisotropy at very low gas pressure below 1 mTorr. The high etch rate is due to the reduction of reaction products density because of the very short gas‐residence time of 30 ms. This technique also dramatically reduces the contamination of reaction products. Etching of crystalline Si and n
+ polycrystalline Si with the high‐flow etching system is demonstrated. For crystalline Si etching with Cl2, a high etch rate up to 1 μm/min is achieved at a high gas flow rate of 90 sccm at 0.5 mTorr.