Study of Si and Ge Atoms Termination Using H-Dilution in SiGe:H Alloys Deposited by Radio Frequency (13.56 MHz) Plasma Discharge at Low Temperature

Abstract

In this work, we present the study of the atomic composition in amorphous SiXGeY:HZ films deposited by radio frequency (RF—13.56 MHz) plasma discharge at low deposition temperature. A study and control of Si and Ge atoms termination using H-dilution in SiGe:H alloys deposited by RF plasma discharge was conducted and we made a comparison with low-frequency plasma discharge studies. Solid contents of the main elements and contaminants were determined by SIMS technique. It was found that for low dilution rates from RH = 9 to 30, the germanium content in the solid phase strongly depends on the hydrogen dilution and varies from Y = 0.49 to 0.68. On the other hand, with a higher presence of hydrogen in the mixture, the germanium content does not change and remains close to the value of Y = 0.69. The coefficient of Ge preferential incorporation depended on RH and varied from PGe = 0.8 to 4.3. Also, the termination of Si and Ge atoms with hydrogen was studied using FTIR spectroscopy. Preferential termination of Si atoms was observed in the films deposited with low RH < 20, while preferential termination of Ge atoms was found in the films deposited with high RH > 40. In the range of 20 < RH < 40, hydrogen created chemical bonds with both Si and Ge atoms without preference.

Review of Si-Based Thin Films and Materials for Thermoelectric Energy Harvesting and Their Integration into Electronic Devices for Energy Management Systems

“…On the other hand, PECVD (plasma-enhanced chemical vapor deposition) is a widely used technique in industries such as microelectronics, photovoltaics, and displays to deposit thin films [95,97,136]. The PECVD process involves plasma generation through an electrical field at a reduced pressure.…”

“…PECVD also allows for material doping via adjustment of precursor gases such as phosphine (PH 3 ) [24,92] and diborane (B 2 H 6 ) [93,99], and LF-PECVD facilitates the production of nanocrystals into the amorphous matrix via high pressure and large hydrogen dilution during the deposition process [95,137,138]. Finally, it is worth mentioning that a fundamental aspect that enables the use of the PECVD technique for thin film deposition is its compatibility with Si-CMOS technology for large scale fabrication and coupling with Si-based TE materials [10,24,136].…”