Study on acceptor level and thermal stability of Si-doped p-type GaAsSb

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05046
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Crystal engineering
• Research Institution: Suzuka National College of Technology
• Principal Investigator: Yokoyama Haruki 鈴鹿工業高等専門学校, その他部局等, 教授 (20583701)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: GaAsSb / ドーピング / Si / p型 / アクセプタ準位 / 移動度 / 拡散

Outline of Final Research Achievements

P-type GaAsSb is a very attractive material because it enables us to improve the performance of III-V compound semiconductor devices. In this study, the temperature dependence of mobility and carrier concentration in Si doped p-type GaAsSb layer were examined. Mobility and carrier concentration were measured in the temperature range from 21K to 292K by the Van der Pauw method. In the calculation of mobility, polarized optical phonon scattering, acoustic phonon deformation potential scattering, ionized impurity scattering, and alloy scattering were taken into consideration. From the calculation, it was found that the mobility of p-type GaAsSb is heavily affected by alloy scattering. By analyzing the temperature dependence of carrier concentration, it was clarified that acceptor level of Si in a p-type GaAsSb is 0.027eV. Furthermore, the thermal stability of Si-doped p-type GaAsSb was investigated and it was found that the Si is stable in GaAsSb up to 500 OC.

Free Research Field

結晶工学

Academic Significance and Societal Importance of the Research Achievements

デバイスを設計するためには、ドーパントがどのようなエネルギー準位を結晶中で形成し、導電性に寄与しているかについて解明することが重要である。本研究では、GaAsSbにドーピングしたSi がどのようなアクセプタ準位を形成するかについて明らかにした。また、ドーピング技術において、設計通りのドーピングを実現すること、つまり、p 型のキャリア濃度がプロセス時の熱等で変動せず、デバイス層を形成した時に拡散のない急峻なドーピングプロファイルを形成できることが要求される。そこで、熱処理を行った時のSiの挙動について調べ、SiドープGaAsSbの熱的安定性を評価した。