liquid Si engineering based on the liquid-to-solid Si conversion

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02180
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Yamanashi Prefectural University (2023); Japan Advanced Institute of Science and Technology (2020-2022)
• Principal Investigator: Masuda Takashi 山梨県立大学, 地域人材養成センター, 特任教授 (70643138)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 液体プロセス / シリコン半導体 / 液体Si

Outline of Final Research Achievements

This research focused on the unique material ``liquid Si'' and aimed to demonstrate the ``liquid-to-solid Si conversion'' induced by electron beam (EB) irradiation, as well as to clarify its mechanism. Using a liquid phase (LP)-electron beam induced deposition (EBID) equipment which was constructed by us, we irradiated EB on liquid Si and demonstrated that liquid-to-amorphous/crystalline Si conversion was induced in the EB irradiation area. The impurity concentration in the obtained solid Si film was below the detection limit of the EDX, and it was a highly pure semiconductor Si film. Montecarlo simulation and Density Functional Theory were used to gain insight into the identification and influence of reactive species in the phase transition. We succeeded direct writing of semiconductor Si thin films without heating/vacuum.

Free Research Field

半導体工学

Academic Significance and Societal Importance of the Research Achievements

申請者らが創出した「液体Si」とは、常温常圧で液体、脱水素化により固体Siとなる新物質である。液体Siを固体Si（半導体Si膜）に変換するためには従来400℃の熱を必要としていたが、本研究では非加熱・非真空でこの変換を達成した。更に直接パターニング技術およびドープSi膜の形成にも成功した。この意義は従来のSi工学では不可能とされてきた、非加熱・非真空でナノスケールの半導体Si膜の直接描画技術の確立にある。その学術的意義は、100年続く固体Si(ウェハ)や気体Si(シランガス)に立脚した従来のSi工学を、「液体」という未踏領域へ推し進めた点にある。