AVS 60th International Symposium and Exhibition
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP31
Novel TSV Etching Technologies using Spatial and Temporal Control Plasma

Tuesday, October 29, 2013, 6:00 pm, Room Hall B

Session: Plasma Science and Technology Poster Session
Presenter: Y. Morikawa, NMEMS and ULVAC, Inc., Japan
Authors: Y. Morikawa, NMEMS and ULVAC, Inc., Japan
T. Murayama, NMEMS and ULVAC, Inc., Japan
T. Sakuishi, NMEMS and ULVAC, Inc., Japan
K. Suu, NMEMS and ULVAC, Inc., Japan
Correspondent: Click to Email
The advantage of high pressure ICP process is lower self bias voltage than capacitive coupled plasma (CCP) to reduction of notching profile for via last process. And, the very high frequency CCP can cause a plasma uniformity issue due to the standing-wave effect. The plasma characteristics of inductive coupled plasma (ICP) source above 10Pa process operated with dual rf antenna coils with magnetic neutral loop discharge (NLD) plasma were investigated for thru silicon via (TSV) etching. Improved plasma characteristics such as higher plasma density and very uniform and high aspect ratio anisotropy TSV etching process were realized in 300mm wafer. Which plasma source is kind of planar type ICP or NLD. 13.56MHz or 2MHz of rf for dual antenna coils and low frequency rf bias can operate in independently. Mechanism of Si etching is mainly fluorine radical reaction. High density plasma is need to get high etch rate. On the other hand, management of radical diffusion from around rf antenna is important for very uniform process of high aspect ratio TSV as well. Center gas injection on the rf window is induced instead of side gas injection to avoid of the rf electric field effect. Therefore, when Si was etched using dual rf antenna coil with SF6 / O2 / SiF4 or SiCl4 mixture gases injection from center of rf window and outer side, the high etch rate and selectivity of Si over the photo-resist and very uniform process were observed. And, the combination of "spatial and temporal control of rf input power on dual rf antenna", and "gases inject apportionment each nozzles (center/outer)" can be controllable in large diameter substrate etching process. This method named “STEVIA” (Spatial and Temporal Control Plasma for Thru Silicon Via Etching).