Title :
A high-temperature thermopile fabrication process for thermal flow sensors
Author :
Buchner, Rainer ; Rohloff, Klaus ; Benecke, Wolfgang ; Lang, Walter
Author_Institution :
Inst. fur Mikrosensoren, -aktuatoren und -systeme, Bremen Univ., Germany
Abstract :
A new high-temperature fabrication process for thermopile-based flow sensors is presented. The high-temperature passivation of LPCVD silicon nitride leads to an improvement for liquid applications because of the low tendency towards pinholes and the good step coverage. The thermopiles are made of p-doped polysilicon and titanium-tungsten. The nitride membrane was released by a DRIE process to achieve a reduced chip size and higher yield compared to established thermal flow sensors. Devices for different flow rates were fabricated and successfully tested, showing good sensitivity and very short reaction time.
Keywords :
flow measurement; membranes; micromachining; microsensors; silicon; silicon compounds; temperature sensors; thermopiles; titanium alloys; tungsten alloys; DRIE process; LPCVD silicon nitride; SiN; TiW; deep RIE process; deep reactive ion etching; high-temperature thermopile fabrication process; nitride membrane; p-doped polysilicon; pinholes; reduced chip size; step coverage; thermal flow sensors; thermopile-based flow sensors; titanium-tungsten; yield; Biomembranes; Fabrication; Fluid flow; Fluid flow measurement; Gas detectors; Infrared sensors; Passivation; Silicon; Temperature sensors; Thermal sensors;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05. The 13th International Conference on
Print_ISBN :
0-7803-8994-8
DOI :
10.1109/SENSOR.2005.1496482
