Deep SiC etching with RIE

Mihai Lazar (1, 2) , Heu Vang (1, 2) , Pierre Brosselard (1, 2) , Christophe Raynaud (1, 2) , Pierre Cremilleu (3) , Jean-Louis Leclercq (4) , A. Descamps (3) , Sigo Scharnholz (5) , Dominique Planson (1, 2)

1 EE - Ampère, Département Energie Electrique
2 INSA Lyon - Institut National des Sciences Appliquées de Lyon
3 INL - Nanolyon - INL - Plateforme Technologique Nanolyon
4 INL - Photonique - INL - Nanophotonique
5 ISL - Institut franco-allemand de recherches de Saint-Louis

SiC is currently an important topic in power devices. This new technology leads to lower power losses, faster switching, and higher working temperature. The design of SiC power devices requires the integration of edge termination techniques to obtain a high blocking voltage. The mesa structure approach is one well-established method. It could be used alone or in combination with a Junction Termination Extension (JTE). The mesa consists of a structure that removes material around the pn-junction. Due to the strong Si-C bonds, conventional chemical-wet etching solutions are inefficient on SiC, so plasma methods are required to etch SiC. The presented work is based on the use of an RIE reactor with an SF6/O-2 plasma. Its geometry structure and parameters were optimized. An etch rate of 0.35 mu m/min was obtained without any trenching phenomenon. Trenches deeper than 10 mu m deep were realized with a nickel etching mask that shows a high selectivity. AFM analysis revealed an etched surface as smooth as the initial one.

Mots clés: reactive ion etching; silicon carbide; surface morphology

Domaines: Energie électrique

Mihai Lazar, Heu Vang, Pierre Brosselard, Christophe Raynaud, Pierre Cremilleu, et al.. Deep SiC etching with RIE. Superlattices and Microstructures, 2006, 40 (4-6), pp.388-392. ⟨10.1016/j.spmi.2006.06.015⟩. ⟨hal-00179458⟩