AVS 47th International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS2-ThA

Paper PS2-ThA2
Temperature and Bias Effects in ICP Etching of Silicon Dioxide

Thursday, October 5, 2000, 2:20 pm, Room 311

Session: Dielectrics I
Presenter: M.J. Cooke, Oxford Instruments Plasma Technology Ltd., UK
Authors: M.J. Cooke, Oxford Instruments Plasma Technology Ltd., UK
G. Hassall, Oxford Instruments Plasma Technology Ltd., UK
Correspondent: Click to Email
Silicon dioxide etching has been evaluated in a new induction-coupled plasma (ICP) source (designated ICP380), with particular attention to the sources of nonuniformity in etching 200 mm wafers. The contributions of the ICP source, the rf bias to the wafer, and the gas flow distribution to uniform etching are examined experimentally, supported by simple models. The implications for the design of etching hardware and for the protocols to achieve reproducible processes are considered. The rate of polymer deposition and etching in fluorocarbon plasmas has been measured as a function of the ion impact energy and the temperature of the substrate, using interferometry and direct film thickness measurements. This has been related to the etch profile evolution for 10 micron deep trenches in thick silicon dioxide layers. It is shown that substrate temperature control is a necessary part of profile control, even for etches which are normally considered to be regulated by ion bombardment.