n+-polysilicon etching with both, high anistropy and high selectivity, for ULSI fabrication has been realized by irradiating the chlorine and nitrogen mixed plasma under a low ion energy condition using an ultraclean ECR etcher. From XPS analysis, it is found that the high anisotropy is caused by the formation of Si-N bonds by N radicals on the shallow surface of n+-polysilicon. Based on the evaluation of the enthalpy change for reactions together with the added N2 dependence of the etch rate, it has been proposed that etching in the N2 added Cl2 plasma can be analyzed as competitive reactions with an equation similar to Langumuir's adsorption isotherm.
|Number of pages||4|
|Publication status||Published - 1990|
|Event||22nd International Conference on Solid State Devices and Materials - Sendai, Jpn|
Duration: 1990 Aug 22 → 1990 Aug 24
|Other||22nd International Conference on Solid State Devices and Materials|
|Period||90/8/22 → 90/8/24|
ASJC Scopus subject areas