AVS 51st International Symposium
    MEMS and NEMS Monday Sessions
       Session MN-MoA

Paper MN-MoA10
Micro-fabricated Charge-sensing Resistive Probe

Monday, November 15, 2004, 5:00 pm, Room 213C

Session: Micro and Nano Fabrication Techniques for MEMS and NEMS
Presenter: H. Park, Samsung Advanced Institute of Technology, Korea
Authors: H. Park, Samsung Advanced Institute of Technology, Korea
J. Jung, Samsung Advanced Institute of Technology, Korea
D.-K. Min, Samsung Advanced Institute of Technology, Korea
C. Park, Samsung Advanced Institute of Technology, Korea
K. Baeck, Samsung Advanced Institute of Technology, Korea
S. Kim, Samsung Advanced Institute of Technology, Korea
H. Ko, Samsung Advanced Institute of Technology, Korea
S. Hong, Samsung Advanced Institute of Technology, Korea
Correspondent: Click to Email
We fabricated a scanning probe microscopy (SPM) probe that can image surface charges of ferroelectric domains at high speed without an additional signal modulation system like a lock-in amplifier. The probe detects electric field by field-induced resistance change in a semiconductor resistive region formed at the apex of the tip; the majority carriers in the resistive region are depleted or accumulated by the electric field. To minimize the size of the resistive region and align it at the apex of the tip, we developed a self-aligning process, which is designed to etch Silicon for tip formation with the same masking material as that used in the preceding ion implant process forming the resistive region. We simulated tip fabrication process using SUPREM IV and confirmed that only low-doped n-type resistive region of 150 nm size existed at the tip apex as designed. In order to measure the field sensitivity, we contacted the fabricated resistive probe on a thermally oxidized silicon sample and measured 0.5 % resistance change per voltage applied to the sample. The response time to the external field was about 10 nsec. We obtained domain images of triglycine sulfate (TGS) single crystal with the probe in contact mode. The operating voltage of the probe was 2 V and the scan rate was 2 Hz. We controlled the polarization of Pb(Zr@sub 0.4@Ti@sub 0.6@)O@sub 3@ (PZT) by applying voltage between the resistive tip and the bottom electrode of PZT, and acquired the domain images with the same probe at 2 Hz scan rate. The diameter of detected domain was 500 nm and the transition width between opposite domain images was about 120 nm. By controlling and detecting the ferroelectric domains without an additional signal modulating system, we verified that the resistive probe could be used for a high speed SPM mapping surface charges and be applied to the probe-based data storage system in which a fast read/write head of simple structure and process is essential.