Space charge layer effects in silicon studied by in situ surface transport

Area of Science:

• Surface science
• Condensed matter physics
• Materials science

Background:

• Surface transport experiments are crucial for studying low-dimensional electronic properties.
• These experiments face challenges in controlling bulk electron paths and internal interfaces due to surface sensitivity.
• Understanding Schottky barriers and space charge layers is vital for silicon surface analysis.

Purpose of the Study:

• To analyze the influence of Schottky barriers and space charge layers on silicon surfaces.
• To investigate subsurface transport channels in vicinal Si(111) using metal submonolayer coverage.
• To understand the impact of high-temperature treatments on surface-near defects.

Main Methods:

• Utilized angle- and temperature-dependent in situ transport measurements.
• Deposited metal submonolayer on vicinal Si(111) to access subsurface transport.
• Performed high-temperature treatments under ultra-high vacuum conditions.

Main Results:

• Successfully accessed subsurface transport channels.
• Identified the formation of surface-near bulk defects, such as SiC-interstitials, after high-temperature treatments.
• Observed that these defects function as p-type dopants, overcompensating n-doped silicon substrates.

Conclusions:

• Schottky barriers and space charge layers play a significant role in silicon surface electronic properties.
• High-temperature treatments can induce defects that alter the electronic behavior of silicon surfaces.
• The formation of p-type dopants from defects can significantly impact subsurface transport in silicon.