Polymer-Sandwich Ultra-Thin Silicon(100) Platform for Flexible Electronics
Yong-Hua Zhang1**, S. Karthikeyan2, Jian Zhang1
1Department of Electronic Science and Engineering, East China Normal University, Shanghai 200241 2Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis 55455, USA
Abstract：As a potential flexible substrate for flexible electronics, a polymer-sandwiched ultra-thin silicon platform is studied. SU-8 photoresist coated on the silicon membrane improves its flexibility as shown by an ANSYS simulation. Using the plasma enhanced chemical vapor deposited SiO$_{2}$/Si$_{3}$N$_{4}$ composite film as an etching mask, a $4''$ silicon-(100) wafer is thinned to 26 μm without rupture in a 30 wt.% KOH solution. The thinned wafer is coated on both sides with 20 μm of SU-8 photoresist and is cut into strips. Then the strips are bent by a caliper to measure its bending radius. A sector model of bending deformation is adopted to estimate the radius of curvature. The determined minimal bending radius of the polymer-sandwiched ultra-thin silicon layer is no more than 3.3 mm. The fabrication process of this sandwich structure can be used as a post-fabrication process for high performance flexible electronics.
2016, Vol. 33 
