Reactive Ion Etching (RIE)

We are interested in understanding the plasma etching mechanism, which includes plasma phase chemistry, plasma-surface reactions, and surface reactions. We specialize in studying etch processes of non-conventional thin-film materials such as copper, indium tin oxide, metal oxides, a-Si:H, SiNx, and SiGex, for future generations of VLSI, TFT, and other microelectronics or opto-electronics. High temperature RIE is a powerful method that has the advantages of a simple reactor design and being easy to transfer to accommodate large substrates (e.g. 12" for VLSI and 1m x 1m for TFT LCDs). Some examples of recent results are shown as follows. For more detailed information, please see the Publications List.

Plasma-Based Copper Dry Etching Process

- the first world record of room temperature plasma etch process

RIE of TiW Cu Barrier and Selectivity to PECVD SiNx



G. Liu and Y. Kuo, JES 154(7) H653 (2007)

Selectivity RIE of PECVD n+ to intrinsic a-Si:H



Y. Kuo and M. Crowder, JES 139(2), 548 (1992).


Selectivity RIE of PECVD n+ to SiNx

Y. Kuo and M. Crowder, JES 139(2), 548 (1992).


RIE of Indium Tin Oxide (ITO)

- Non-Additive Feed Gas Effect and Loading Factors

Y. Kuo, JES 145(12) 4313 (1998)

HBr Etched

HBr/CH4 (60%) Etched

Y. Kuo, ECS Plasma Processing Symp. Proc. XII, 1998.

Surface Reactions

Temperature Effect


        Y. Kuo, JJAP 2(5B), L629(1997).




     Y. Kuo and T. L. Tai, JECS, 1998 






Modification of Patterned Photoresist

hydrogeantion of photoresist

Hydrogenated photoresist is more resistant to plasma etching

Y. Kuo, APL, 2 (1A1B), L 126, 1993.


Plasma Damages to TFTs and Repairment


Y. Kuo, APL, 61(23), 2790, 1992

Bulk Damage                                           Surface Damage


Y. Kuo and M. Crowder, JES 139(2), 548 (1992).

Profile Control

Etch Rate Ratio R

RIE Etched Sloped Molybdenum

Y. Kuo, et. al., J. Vac. Sci. Technology, A8(2), 1529, 1990.

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