TY - JOUR
T1 - Atomic layer defect-free etching for germanium using HBr neutral beam
AU - Fujii, Takuya
AU - Ohori, Daisuke
AU - Noda, Shuichi
AU - Tanimoto, Yosuke
AU - Sato, Daisuke
AU - Kurihara, Hideyuki
AU - Mizubayashi, Wataru
AU - Endo, Kazuhiko
AU - Li, Yiming
AU - Lee, Yao Jen
AU - Ozaki, Takuya
AU - Samukawa, Seiji
N1 - Funding Information:
This work was supported in part by the CREST program of the Japan Science and Technology (JST) Agency, the Ministry of Science and Technology (MOST), Taiwan, under Grant Nos. MOST 106-2221-E-009-149, MOST 106-2622-8-009-013-TM, 107-2622-8-009-011-TM, 107-2221-E-009-094, and MOST 107-3017-F-009-001, and by the Center for Millimeter-Wave Smart Radar Systems and Technologies under the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan.
Publisher Copyright:
© 2019 Author(s).
PY - 2019/9/1
Y1 - 2019/9/1
N2 - The authors developed extremely selective etching for making an atomically flat, defect-free germanium fin (Ge Fin) structure. The etching uses a hydrogen bromide (HBr) neutral beam (NB), and they investigated the etching reaction differences between the HBr NB and a Cl2 NB. No sidewall etching by HBr NB occurred at 90 °C, although that by Cl2 NB occurred at more than 90 °C. This was due to the different boiling points of GeBr4 and GeCl4 as the reacted layer was formed by NB irradiation on the Ge surface. As a result, the Ge sidewall etching by Cl2 NB occurred above 90 °C, whereas that by HBr NB did not occur at 90 °C. Additionally, nonvolatile bromide protected layers, such as GeBr4 and SiBrxOy, were deposited on the Ge sidewall and the SiO2 top surface in case of using HBr, respectively. Then, the authors succeeded in fabricating the atomically flat, defect-free Ge Fin structure with the extremely selective HBr NB etching. This result shows that HBr NB can more precisely achieve sub-10-nm scale atomic layer Ge etching for 3D Fin-type MOSFETs.
AB - The authors developed extremely selective etching for making an atomically flat, defect-free germanium fin (Ge Fin) structure. The etching uses a hydrogen bromide (HBr) neutral beam (NB), and they investigated the etching reaction differences between the HBr NB and a Cl2 NB. No sidewall etching by HBr NB occurred at 90 °C, although that by Cl2 NB occurred at more than 90 °C. This was due to the different boiling points of GeBr4 and GeCl4 as the reacted layer was formed by NB irradiation on the Ge surface. As a result, the Ge sidewall etching by Cl2 NB occurred above 90 °C, whereas that by HBr NB did not occur at 90 °C. Additionally, nonvolatile bromide protected layers, such as GeBr4 and SiBrxOy, were deposited on the Ge sidewall and the SiO2 top surface in case of using HBr, respectively. Then, the authors succeeded in fabricating the atomically flat, defect-free Ge Fin structure with the extremely selective HBr NB etching. This result shows that HBr NB can more precisely achieve sub-10-nm scale atomic layer Ge etching for 3D Fin-type MOSFETs.
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U2 - 10.1116/1.5100547
DO - 10.1116/1.5100547
M3 - Article
AN - SCOPUS:85070089735
VL - 37
JO - Journal of Vacuum Science and Technology A
JF - Journal of Vacuum Science and Technology A
SN - 0734-2101
IS - 5
M1 - 051001
ER -