Silicon Membranes for Smart Silicon Sensors .

S. Kal; S. Das; S. K. Lahiri

doi:10.14429/dsj.48.3969

S. Kal Indian Institute of Technology Kharagpur, Kharagpur
S. Das Indian Institute of Technology Kharagpur, Kharagpur
S. K. Lahiri Indian Institute of Technology Kharagpur, Kharagpur

DOI: https://doi.org/10.14429/dsj.48.3969

Keywords: Microelectromechanical sensors, Infrared detector, Anisotropic etching, Microsensors

Abstract

The development of smart Si sensors which combine active circuitry and sensor on the same chip, has drawn attention in terms of miniaturisation and cost-effectiveness of microsensors. Interest in micromachining of Si to fabricate membranes derives from the need for inexpensive and more versatile sensors. This paper reports the results on fabrication of Si membranes by anisotropic etching of Si in EDP solution. Good quality membranes of 10 Nanometer thickness were fabricated. Infrared detector based on thermopile structure was realised on 50 Nanometer thick Si membrane using polysilicon and Al junctions. Thermo-emf generated at 150 °c is nearly 8 mv.

Author Biographies

S. Kal, Indian Institute of Technology Kharagpur, Kharagpur

Dr s Kal received his PhD in Electronics & Electrical Communication Engineering from the Indian
Institute of Technology (lIT). Kharagpur. in 1983. He visited Ruhr University, Bochum, West Germany. as a DAAD fellow during the period 1984-85 and worked on technology for isoplanar oxide isolated integrated injection logic. He joined lIT, Kharagpur in 1986 and presently. he is Associate Professor in the Department of Electronics & ECE. He visited the University of Erlangen-Nurnberg. Germany. under DAAD re-invitation programme and worked on shallow junction devices for sub micron VLSI during May-July 1993. He was awarded International Exchange Fellowship-1997 by INSA. New Delhi and visited Germany for five months. He has published more than 60 research papers in national and international journals. He played a key role in setting up the Microelectronics Centre at lIT for carrying out experimental research in silicon devices and ICs. He has conducted many students. projects and PhD programmes in bipolar devices and ICs. His current research activities include ASICs. metallisation problems in submicron VLSI. special semiconductor films. microsensors and MEMS. He is working in close collaboration with DRDO. ISRO and industries like BEL. Bangalore. He is a member of the Institution of Engineers (India) and IEEE (USA).

S. Das, Indian Institute of Technology Kharagpur, Kharagpur

Dr S Das received his MSc in Physics from the IIT, Kharagpur, in 1988. He joined at the Microelectronics Centre, Dept. of Electronics and ECE, IIT Kharagpur, in 1989 as a CSIR Research
Fellow. He received his PhD in 1996 on large bias conduction in polysilicon, high current pulse trimming of polyresistors and transient studies of polysilicon fuses. Presently, he is working as
Scientific Officer in Microelectronics Centre of E & ECE Department. He has been involved in
experimental research on ion beam processing for VLSI like dual ion beam deposition of oxynitride
films of controllable composition, chemicp.lly assisted ion beam etching and poly silicon film
deposition and characterisation. He is also involved in the fabrication and characterisation of silicon
bipolar devices and integrated circuits, development of micromachining technology and microsensors.

S. K. Lahiri, Indian Institute of Technology Kharagpur, Kharagpur

Dr SK Lahiri received his BSc (Physics) from the Presidency College, Calcutta, in 1963, MTech
and PhD both from the Institute of Radio Physics & Electronics, Calcutta University in the years
1966 and 1971, respectively. He joined lIT, Kharagpur, in 1971 in the Department of Electronics &
Elec. Comm. Engg. He has been working a5 Professor since 1985. He started his research career in
solidstate electronics and SAW devices. He played a key role in setting up the Microelectronics
Centre at lIT for carrying out experimental research in silicon devices and ICs. He has conducted
many students' projects and PhD programmes in the areas of microelectronics and SAW devices and
led research teams to undertake sponsored R&D programmes in bipolar device modelling andprocess simulation. His current research activities include integrated optics, power ICs, special semiconductor films, microsensors and MEMs. He is working in close collaboration with DRDO, ISRO, industries like BEL, Bangalore. He has published about eighty research papers. He has served as a member of National Microelectronics Council Technology Working Group, CSIR Manpower Assessment Board, Board of Examiners of several universities and Project Review Committees of DOE and ISRO.