Investigation of the Integration of Strained Ge Channel with Si-Based FinFETs

Abstract

In this manuscript, the integration of a strained Ge channel with Si-based FinFETs was investigated. The main focus was the preparation of high-aspect-ratio (AR) fin structures, appropriate etching topography and the growth of germanium (Ge) as a channel material with a highly compressive strain. Two etching methods, the wet etching and in situ HCl dry etching methods, were studied to achieve a better etching topography. In addition, the selective epitaxial growth of Ge material was performed on a patterned substrate using reduced pressure chemical vapor deposition. The results show that a V-shaped structure formed at the bottom of the dummy Si-fins using the wet etching method, which is beneficial to the suppression of dislocations. In addition, compressive strain was introduced to the Ge channel after the Ge selective epitaxial growth, which benefits the pMOS transport characteristics. The pattern dependency of the Ge growth over the patterned wafer was measured, and the solutions for uniform epitaxy are discussed.

FinFET to GAA MBCFET: A Review and Insights

“…Buqing et al [111] in 2022, has integrated strained Ge channel with Si-based FinFETs to improve the aspect-ratio (AR). A selective epitaxial growth process for Ge material was executed on a patterned substrate using reducedpressure chemical vapor deposition (CVD).…”

CMOS Scaling for the 5 nm Node and Beyond: Device, Process and Technology

“…There is also special-shaped fin etching, which uses oxidation to obtain isolation from the substrate to achieve the effect of SOI [243], and scallop to obtain better gate control [244,245]. In addition, facing the etching countermeasures of new channel materials, such as Ge and SiGe and SiGe/Ge FinFET [246,247], hydrogen plasma is introduced as a new way to control morphology and CD (critical dimension) [248].…”