Crystalline GeSn growth by plasma enhanced chemical vapor deposition

Abstract

Single crystalline GeSn growth on Si substrate was successfully demonstrated by using plasma enhanced chemical vapor deposition (PE-CVD) with commercially available GeH4 and SnCl4 precursors. Using the plasma enhancement technique, low temperature growth at 350°C for GeSn epitaxy on Si substrate was achieved with the growth rate of 51.4 nm/min and Sn content up to 6%. The relaxed GeSn films with 1 µm thickness were able to be grown despite of the huge lattice mismatch between GeSn and Si. Structural and optical characterizations were conducted to study the film properties. The demonstrated plasma enhancement growth showed its effectiveness to enhance the Sn incorporation of the crystalline GeSn at low temperature and to maintain the high growth rate.