Title :
Deep reactive ion etching of silicon using an aluminum etching mask
Author :
Wang, Wei-Chili ; Ho, Joe Nhut ; Reinhall, Per
Author_Institution :
Dept. of Mech. Eng., Univ. of Washington, Seattle, WA, USA
Abstract :
A method for fast and efficient deep etching of bulk silicon, using parallel capacitively coupled plasma is presented. The effects of the masking materials and RIE conditions are discussed. Based on the experimental results, a 1000 Å thick Al film sufficiently protects the unexposed substrate while allowing the etching of a 350 μm deep hole with an area of 3×3mm2 when etching with SF6/CHF3/O2 plasma. A 2000 μm long and 100 μm wide (with layers of Al/SiO2/Si and thickness of 0.1μm/2.2μm/40μm respectively) cantilever has been achieved. A silicon etch rate up to 2.5 to 2.8μm/min has been obtained and an anisotropy of A = 0.5 (A=I-V/H, where V=horizontal undercut, H=etch depth) has been obtained. The technique was developed mainly for bulk micromachining of silicon or composite silicon cantilever structures.
Keywords :
aluminium; elemental semiconductors; masks; micromachining; plasma chemistry; reaction rate constants; silicon; sputter etching; surface chemistry; 0.1 micron; 100 micron; 2.2 micron; 2000 micron; 3 mm; 350 micron; 40 micron; Al; Al-SiO2-Si; Al/SiO2/Si; O2; RIE conditions; SF6; SF6/CHF3/O2 plasma; Si; aluminum etching mask; anisotropy; bulk micromachining; bulk silicon; cantilever; composite silicon cantilever structures; deep reactive ion etching; etch depth; etch rate; hole; horizontal undercut; masking materials; parallel capacitively coupled plasma; silicon; unexposed substrate; Aluminum; Anisotropic magnetoresistance; Artificial intelligence; Dielectric materials; Etching; Fabrication; Oxidation; Protection; Silicon; Structural beams;
Conference_Titel :
Advanced Semiconductor Devices and Microsystems, 2002. The Fourth International Conference on
Print_ISBN :
0-7803-7276-X
DOI :
10.1109/ASDAM.2002.1088467
