Effect of Chamber Conditions and Substrate Type on PECVD of SiGeSn Films

Abstract

In the past studies have shown that the addition of Ge and Sn into Si lattice to form SiGeSn enhances its carrier mobility and band-gap properties. Conventionally SiGeSn epitaxial films are grown using Ultra-High Vacuum (UHV) conditions with pressures ranging from 10 −8 torr to 10 −10 torr which makes high volume manufacturing very expensive. On the contrary, the use of lowpressure CVD processes (vacuum levels of 10 −2 torr to 10 −4 torr) is economically more viable and yields faster deposition of SiGeSn films. This study outlines the use of a cost-effective Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor to study the impact of substrate temperature and substrate type on the growth and properties of polycrystalline SiGeSn films. The onset of polycrystallinity in the films is attributed to the oxygen-rich PECVD chamber conditions explained using the Volmer-Weber (3D island) mechanism. The properties of the films were characterized using varied techniques to understand the impact of the substrate on film composition, thickness, crystallinity, and strain.

Characterization of Polish-Induced Gouges on Single Crystal Sapphire Substrates

“…The FWHM denotes the crystalline quality of material, which is related to dislocation defect density as reported in several prior investigations. [17][18][19][20] The FWHM numbers for all polishing processed C-and A-plane substrates is ranged 0.0035-0.0049°and 0.0094-0.0105°, respectively. The FWHM values between mechanically polished coupons and CMP polished coupons are nearly indistinguishable and did not show any trends to assess polishing induced defects with the various conditions.…”