Electrical characterization of silicon tips using conducting atomic force microscopy.
The electrical properties of n-doped Si tips have been characterized in conducting atomic force microscopy under various conditions. Si tips with SiO2 layer on them present complex electric properties: which include a larger positive threshold bias, which is different from that of its doped semiconductor material. Silicon tips after removing their SiO2 layer had smaller positive threshold bias; such bias varied with the loading force: smaller loading forces corresponding to larger positive threshold biases, and it remained constant at lower levels for larger loading forces. Humidity of experiments influenced the threshold bias: lower relative humidities (<25%) and larger loading forces were in favor of getting stable threshold bias. The conductance increased remarkably in high relative humidity although it was kept in a narrow range when relative humidity was lower than 40%. Loading force didn't affect the conductance in the examined relative humidity conditions. One advantage of bare silicon tips over commercial conducting ones is that they smaller radius than gold-coated tips; this is in more favor of reaching single molecular electronics.
Xiao
Xinxing
X
Department of Biological Science and Medical Engineering, Key Lab of Molecular and Biomolecular Electronics, Ministry of Education, Southeast University, Nanjing, P R. China.
Xiao
Zhongdang
Z
Lu
Zuhong
Z
D004553:Electric Conductivity; D004563:Electrochemistry; D006813:Humidity; D018625:Microscopy, Atomic Force / Q000295:instrumentation*; D036103:Nanotechnology; D012825:Silicon; D012822:Silicon Dioxide
D012822:Silicon Dioxide; D012825:Silicon