Title :
Improvement of Si/SiO/sub 2/ mask etching selectivity in the new D-RIE process
Author :
Ohara, J. ; Kano, K. ; Takeuchi, Y. ; Otsuka, Y.
Author_Institution :
Res. Lab., DENSO Corp., Nisshin, Japan
Abstract :
This paper describes an improvement of Si/SiO/sub 2/ mask etching selectivity in the new D-RIE process that we presented in MEMS 2000. This process, which repeats the conventional D-RIE (ASE process) and O/sub 2/ plasma irradiation processes alternately, can improve the aspect ratio due to the prevention of lateral etching. However, the SiO/sub 2/ mask erosion of this process was 2.7 times as high as that of the conventional D-RIE process because the SiO/sub 2/ mask is sputtered by oxygen ion in the O/sub 2/ plasma irradiation process. Therefore the highest aspect ratio:46 was restricted by mask consumption. In this study, we suppressed the SiO/sub 2/ mask consumption. This suppression improves etching selectivity and increases the highest aspect ratio up to 60. Furthermore, the required process time is reduced to 2/3 of the prior result.
Keywords :
elemental semiconductors; masks; micromechanical devices; silicon; silicon compounds; sputter etching; ASE process; D-RIE process; MEMS technology; O/sub 2/ plasma irradiation; Si-SiO/sub 2/; Si/SiO/sub 2/ mask etching selectivity; aspect ratio; mask erosion; Condition monitoring; Electrodes; Plasma applications; Plasma density; Plasma devices; Plasma measurements; Plasma temperature; Protection; Radio frequency; Sputter etching;
Conference_Titel :
Micro Electro Mechanical Systems, 2001. MEMS 2001. The 14th IEEE International Conference on
Conference_Location :
Interlaken, Switzerland
Print_ISBN :
0-7803-5998-4
DOI :
10.1109/MEMSYS.2001.906482
