Electrical Characteristics of Si0.8Ge0.2 p-MOSFET With TMA Pre-Doping and NH3 Plasma IL Treatment

• Published in: IEEE transactions on electron devices Vol. 69; no. 4; pp. 1776 - 1780
• Main Authors: Lee, Meng-Chien, Chung, Nien-Ju, Lin, Hung-Ru, Lee, Wei-Li, Chung, Yun-Yan, Wang, Shin-Yuan, Luo, Guang-Li, Chien, Chao-Hsin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum; Ammonia; Doping; Germanium; Interface passivation; Logic gates; MOSFET circuits; MOSFETs; p-MOSFET; Photoelectrons; Plasmas; remote plasma nitridation; SiGe channel; Silicon; Silicon germanides; Silicon germanium; Substrates; trimethylaluminum (TMA) pre-doping; X ray photoelectron spectroscopy
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2022.3153425

We successfully fabricated p-MOSFETs on Si 0.8 Ge 0.2 substrate using trimethylaluminum (TMA) pre-doping and NH 3 plasma as interfacial layer (IL) treatment for HfO 2 -based gate stacks. X-ray photoelectron spectroscopy (XPS) findings indicated that SiGe interface with TMA pre-doping and NH 3 plasma was free from Ge-O bonds and mainly composed of Si-N and Al-O bonds. With this IL treatment, p-MOSFET revealed an improved subthreshold swing of 98 mV/decade and a high <inline-formula> <tex-math notation="LaTeX">{I}_{ \mathrm{ON}} / {I}_{ \mathrm{OFF}} </tex-math></inline-formula> ratio of <inline-formula> <tex-math notation="LaTeX">6\times 10^{{6}} </tex-math></inline-formula>. Furthermore, the <inline-formula> <tex-math notation="LaTeX">{I}_{D} </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">{V}_{D} </tex-math></inline-formula> curves of p-MOSFET showed that the driving current was enhanced from 0.5 to <inline-formula> <tex-math notation="LaTeX">1.8~\mu \text{A} / \mu \text{m} </tex-math></inline-formula> at <inline-formula> <tex-math notation="LaTeX">{V}_{D} = -1 </tex-math></inline-formula> V. Therefore, the proposed scheme is a simple technique to achieve a high-quality interface on a SiGe substrate.