Interface Electric Field Confinement Effect of High-Sensitivity Lateral Ge/Si Avalanche Photodiodes

• 来源期刊: 清华大学学报自然科学版（英文版）
• 年，卷（期）: 2019,（1）
• 页码范围: 1-8
• 页数: 8页
• 语种: 英文
• DOI: 10.26599/TST.2018.9010065

摘要

A novel lateral Ge/Si avalanche photodiode without a charge region is investigated herein using device physical simulation.High field is provided by the band-gap barrier and build-in field at the Ge/Si interface in the vertical direction.Modulating the Si mesa thickness (0-0.4μm) and impurity concentration of the intrinsic Si substrate (1 × 1016-4 × 1016 cm-3) strengthens the electric field confinement in the substrate region and provides a high avalanche multiplication in the Si region.When the Si mesa thickness is 0.3 μm,and the impurity concentration of the Si substrate is 2 × 1016cm-3,the Lateral Avalanche PhotoDiode (LAPD) exhibits a peak gain of 246 under 1.55 μm incident light power of-22.2dBm,which increases with decreasing light intensity.