SiGe based grating light valves

Research Area: Micro-optics and Diffractive Structures

Main Researcher: Sukumar Rudra

With the increased interest in monolithic integration of MEMS and ICs, poly-Si is not a feasible option anymore because of its high deposition temperature of~ 800°C by which all the metallic connection of the CMOS are deteriorated. On the other hand poly-SiGe has a lower deposition temperature of ~ 450°C but the properties are closely comparable to Poly-Si.
So, our aim is to use SiGe to form optical MEMS components like grating light valves (GLV) which can be directly integrated on top of CMOS in future. It consists of free standing beams which can be modulated by applying voltage, in the non actuated state it behaves like a mirror whereas when alternative beams are actuated they form a grating and about 74% of incident light is diffracted in the ±1st order hence it can be used as a pixel.

Operational method of a GLV

Other people involved:

• Joris Roels
• Sukumar Rudra

Publications

International Journals


1. S. Rudra, J. De Coster, R. Van Hoof, G. Bryce, S. Severi, A. Witvrouw, D. Van Thourhout, Static and dynamic characterization of pull-in protected CMOS compatible poly-SiGe grating light valves, Sensors and actuators A, 179, p.283-290 doi:10.1016/j.sna.2012.03.034 (2012)  .
2. S. Rudra, J. Roels, G. Bryce, L. Haspeslagh , A. Witvrouw , D. Van Thourhout, SiGe based Grating Light Valves: A leap towards monolithic integration of MOEMS, Microelectronic Engineering, 87, p.1195-1197 doi:10.1016/j.mee.2009.12.015 (2010)  .