Pattern-Dependent Charging and the Role of Electron Tunneling
- 1 April 1998
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 37 (4S) , 2281
- https://doi.org/10.1143/jjap.37.2281
Abstract
We review the prevailing causes of and remedies for profile distortion (notching) resulting from pattern-dependent charging during etching in high density plasmas. A new mechanism for notch reduction, based on electron tunneling through thin gate oxides, is explained through detailed modeling and simulations of charging and profile evolution in polysilicon gate definition. Tunneling currents from the substrate decrease surface charging potentials–responsible for ion deflection–at the bottom of high aspect ratio trenches. The exponential dependence of electron tunneling on the oxide electric field predicts an abrupt transition from severe notching to virtually no notching as the gate oxide thickness is decreased, which has been seen in experiments.Keywords
This publication has 38 references indexed in Scilit:
- Simulation of current transients through ultrathin gate oxides during plasma etchingApplied Physics Letters, 1997
- On the Origin of Charging Damage during Etching of Antenna StructuresJournal of the Electrochemical Society, 1997
- On the link between electron shadowing and charging damageJournal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1997
- Electron irradiance of conductive sidewalls: A determining factor for pattern-dependent chargingJournal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1997
- Aspect-ratio-dependent charging in high-density plasmasJournal of Applied Physics, 1997
- Prediction of multiple-feature effects in plasma etchingApplied Physics Letters, 1997
- Silicon etching by alternating irradiations of negative and positive ionsPlasma Sources Science and Technology, 1996
- Pulse-time modulated electron cyclotron resonance plasma etching for highly selective, highly anisotropic, and less-charging polycrystalline silicon patterningJournal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1994
- Microscopic uniformity in plasma etchingJournal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1992
- Tunneling of electrons from Si into thermally grown SiO2Solid-State Electronics, 1977