Development of Crystallized Thick, Highly Doped A-SI:H Layers for Surface Micromachining of MEMS

This study presents the results of a process development for the fabrication of crystallized, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$15-20\ \mu \mathrm{m}$</tex> thick, and highly doped amorphous silicon (a-Si:H) layers suitable for MEMS applications. Utilizing plasma-enhanced chemical vapor deposition (PECVD) followed by crystallization, the approach aims to fabricate a blister-free, highly conductive, and low-roughness polysilicon layer. Additionally, the approach allows the engineering of the mechanical properties of the poly-silicon layers to achieve low layer stress and minimal stress gradients. These achievements lead to improved electrical conductivity and mechanical stability for future MEMS devices.