Observation of low-resistance Al and Ni p-type ohmic contacts to dilute GeC and GeCSn alloys

Nickel and aluminum ohmic contacts were formed on p-doped GeC and GeCSn epitaxial films with ∼1%C. When a 40 nm p-GeC contact layer was added to p-Ge, annealed contact resistivity (Rc) dropped by 87% to 9.3 × 10−7 Ω cm2 for Al but increased by 32% to 2.9 × 10−5 Ω cm2 for Ni. On the other hand, thick films of GeCSn, which showed lower active doping, had contact resistivities of 4.4 × 10−6 Ω cm2 for Al and 1.4 × 10−5 Ω cm2 for Ni. In general, Al contacts were better than Ni, regardless of anneal, and were further improved by adding carbon. Annealing reduced Rc for both Ni and Al contacts to GeCSn by 4×, 2× for Al on GeC, and 5 orders of magnitude for Ni on GeC. It is speculated that C forms bonds with Ni that inhibit diffusion of Ni into the Ge, thus preventing the formation of low-resistance nickel germanide. Adding C, either as bulk GeCSn or as GeC contact layers, seems to significantly reduce the contact resistivity for Al contacts when compared to bulk Ge of comparable doping.

Authors

Institutions

Publication Details

Journal
Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics Materials Processing Measurement and Phenomena
Published
2024-12-01
DOI
https://doi.org/10.1116/6.0003739
Primary Topic
Semiconductor materials and interfaces
Type
article
Field-Weighted Citation Impact
0.00

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Observation of low-resistance Al and Ni p-type ohmic contacts to dilute GeC and GeCSn alloys

Seth R. Bank, Augustus W. Arbogast, Daniel Wasserman, Imteaz Rahaman et al.
Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics Materials Processing Measurement and Phenomena
Semiconductor materials and interfaces
article

Observation of low-resistance Al and Ni p-type ohmic contacts to dilute GeC and GeCSn alloys

Seth R. Bank, Augustus W. Arbogast, Daniel Wasserman, Imteaz Rahaman, Andrei Dolocan, K H Khalili Alam, Pallab Kumar Sarkar, Tuhin Dey, Mark A. Wistey, Jibesh Kanti Saha, Saif Taqy, Md. Reaz Rahman Munna
article en

Abstract

Nickel and aluminum ohmic contacts were formed on p-doped GeC and GeCSn epitaxial films with ∼1%C. When a 40 nm p-GeC contact layer was added to p-Ge, annealed contact resistivity (Rc) dropped by 87% to 9.3 × 10−7 Ω cm2 for Al but increased by 32% to 2.9 × 10−5 Ω cm2 for Ni. On the other hand, thick films of GeCSn, which showed lower active doping, had contact resistivities of 4.4 × 10−6 Ω cm2 for Al and 1.4 × 10−5 Ω cm2 for Ni. In general, Al contacts were better than Ni, regardless of anneal, and were further improved by adding carbon. Annealing reduced Rc for both Ni and Al contacts to GeCSn by 4×, 2× for Al on GeC, and 5 orders of magnitude for Ni on GeC. It is speculated that C forms bonds with Ni that inhibit diffusion of Ni into the Ge, thus preventing the formation of low-resistance nickel germanide. Adding C, either as bulk GeCSn or as GeC contact layers, seems to significantly reduce the contact resistivity for Al contacts when compared to bulk Ge of comparable doping.

Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics Materials Processing Measurement and PhenomenaVol. 42(6)
Texas State University (US), The University of Texas at Austin (US)
National Science Foundation, Air Force Office of Scientific Research
Clean water and sanitation
Openalex Percentile: Top 80%
Semiconductor materials and interfaces
DOISourceOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.