Atomically resolved imaging on semiconductor surfaces with noncontact atomic force microscopy

Seizo Morita and Yasuhiro Sugawara

Department of Electronic Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871, Japan

Recently, the noncontact atomic force microscope (NC-AFM) developed as a unique atomic tool based on a mechanical method. In this presentation, we will introduce recent experimental results of our NC-AFM research for the semiconductor surfaces as follows: 1. Contact point and noncontact imaging of p-GaAs(110). 2. Site dependent frequency shift curves on Si(111)7x7 surface and the effect of oxidized tip. 3. Tip-sample distance dependence of NC-AFM image on Si(111)ˆ3xˆ3-Ag surface with Si tip and Ag adsorbed tip. 4. NC-AFM imaging of Si(111)5ˆ3x5ˆ3-Sb with Si tip and Sb adsorbed tip. 5. NC-AFM images of Si(100)2x1, Si(100)2x1:H monohydride and Si(100)1x1:H dihydride surfaces. 6. Defects imaging and defect motion on semi- insulating InP(110) surface. 7. Imaging of atomic point charges and screening electron clouds on n-GaAs(110) surface. From these experiments, we will discuss imaging mechanisms and force mechanisms between tip atoms and semiconductor surface atoms.