Boosting Ge-Epi P-Well Mobility & Crystal Quality with Si or Sn Implantation and Melt Annealing

• Published in: ECS transactions Vol. 86; no. 7; pp. 357 - 372
• Main Authors: Borland, John O, Chaung, Shang-Shuin, Tseng, Tseung-Yuen, Joshi, Abhijeet, Basol, Bulent, Lee, Yao Jen, Kuroi, Takashi, Tabata, Toshiyuki, Huet, Karim, Goodman, Gary, Khapochkina, Nadya, Buyuklimanli, Temel
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society, Inc 20.07.2018
• ISSN: 1938-5862; 1938-6737; 1938-6737; 1938-5862
• DOI: 10.1149/08607.0357ecst

We investigated the effects of Si, Sn and cluster-C implantation into both P-well and N-well doped regions of Ge-epi on Si wafers after laser annealing. XRD analysis shows improved Ge-epi crystallinity after >1.5J/cm2 laser melt annealing (liquid phase epitaxial regrowth) compared to sub-melt annealing (solid phase epitaxial regrowth). For the P-well case the Ge-epi Rs decreased to 1,600Ω/□ compared to Si at 3,400Ω/□ suggesting a hole mobility increase of 2.1x from 150cm2/V-s to 315cm2/V-s but actual measured Hall mobility was 650cm2/V-s to a depth of 60nm, an increase of 4.3x. The 1.8J/cm2 laser melt anneal with Si implant improved mobility uniformly to 700cm2/V-s to a depth of 100nm while Sn implant improved mobility to 900cm2/V-s from the Ge-epi surface to a depth of 70nm then increases to 3000cm2/V-s at a depth of 100nm. Measuring mobility depth profiles can be very critical in engineering surface and bulk mobility improvements which can be determined by chemical compositional changes in the Ge-epilayer especially for C where no liquid phase diffusion or movement could be detected.