Development of GeSn-based NIR sensing devices

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02620
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: Kwansei Gakuin University (2021-2022); Osaka University (2020)
• Principal Investigator: Hosoi Takuji 関西学院大学, 工学部, 准教授 (90452466)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: GeSn / 赤外線 / 結晶化 / レーザー

Outline of Final Research Achievements

To develop an infrared sensing platform using germanium-tin (GeSn) semiconductor, we investigated the lateral growth of high-quality GeSn single crystals by laser crystallization. After processing an amorphous GeSn layer into a wire shape on a quartz substrate and capping it with a SiO2 layer, we successfully formed the mm-long single-crystalline GeSn wires from end to end by scanning a laser beam. PL and Raman analysis revealed that the formed GeSn wire has excellent crystallinity. In addition, a horizontal double heterostructure with a high Sn concentration GeSn region in the center of the wire was fabricated by scanning the laser twice; Once the entire GeSn wire was crystallized by 1st laser scanning, and 2nd scan was done in the opposite direction and was terminated at the center of the wire.

Free Research Field

半導体工学

Academic Significance and Societal Importance of the Research Achievements

GeSnは集積回路や赤外光学素子として優れた物性を持つと予想される一方で、高品質なGeSn単結晶が困難である。本研究では、高品質GeSn単結晶の横方向液相成長をレーザー走査で行うGeSnレーザー結晶化技術をさらに発展させ、光吸収キャップ層を用いることによるGeSnパターン依存性の解消、レーザー走査の工夫によりGeSnダブルヘテロ構造の作製、などを実現した。また、石英基板に限らずSi基板上でもGeSnレーザー結晶化が可能であることも見出した。