AVS 53rd International Symposium
    MEMS and NEMS Tuesday Sessions
       Session MN-TuP

Paper MN-TuP2
Mechanical Quality Factor Measurement of Micro Structure According to Vacuum Range and Temperature Variation

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Aspects of MEMS and NEMS Poster Session
Presenter: J.S. Kim, Korea University
Authors: J.S. Kim, Korea University
W.B. Kim, Samsung Advanced Institute of Technology, Korea
K.D. Jung, Samsung Advanced Institute of Technology, Korea
M.S. Choi, Samsung Advanced Institute of Technology, Korea
K.W. Nam, Samsung Advanced Institute of Technology, Korea
I.S. Song, Samsung Advanced Institute of Technology, Korea
B.K. Ju, Korea University
Correspondent: Click to Email
In this paper, the Mechanical quality factor of a micro gyro structure according to vacuum range at room temperature and 75°C is measured. On the SOI wafer, gyroscope structures with a comb drive are patterned with a photo-resist (PR) and vertically etched with the ICP-RIE. After the etching process, this micro structure wafer is diced into proper size and released by the oxide layer etching in BOE (buffered oxide etcher). The test circuit and diced micro structure wafer are placed in a chamber with heater that can control vacuum range and substrate temperature. The circuit board is connected with the signal analyzer(HP35670A) and the power supplier by using the feed-through of the chamber. The chamber is vacuated to the specific vacuum range, which can be controlled particularly by using the air release valve. When the vacuum is set to a specific range, the frequency and damping coefficient are read from signal analyzer and translated to the Q-factor. In this way, Q-factors as vacuum range of gyro structures are measured. The measured Q-factor and vacuum range are 3000 to 50000 and 1Torr to 50mTorr. Sample is measured at room temperature and 75°C of substrate temperature, and we found that Q-factor 4000 matched the Vacuum 740mTorr range. From these data, we can fabricate the wafer level package(WLP) gyro-chip that has the desired Q-factor range, controlled by the basic pressure of package bonding chamber.