Spts Technologies Limited

Roland Mumford

Huma Ashraf

Kevin Riddell

Christopher Jonathan W Bolton

Grant Baldwin

Surface roughness on a non-planar surface of a silicon substrate with upstanding and/or recessed features can be reduced. A first sequence of plasma processing steps and a second sequence of plasma processing steps can be performed on the silicon substrate to reduce the surface roughness of the upstanding and/or recessed features while retaining these features. The first sequence of plasma processing steps includes i) a plasma deposition step using oxygen and at least one fluorocarbon gas followed by ii) a plasma etch step using oxygen, at least one fluorocarbon etchant gas, and SF. The second sequence of plasma processing steps includes i) an isotropic plasma etch step using oxygen and at least one fluorine containing etchant gas followed by ii) a plasma etch step using at least one fluorine containing or chlorine containing etchant gas.

Method of reducing surface roughness

A method and system are for monitoring and controlling deformation of a wafer substrate during a plasma etching of the wafer substrate. The method includes disposing a wafer substrate on a platen assembly within a process chamber so that an entire upper surface of the wafer is exposed, passing a process gas into the process chamber, applying a radio frequency bias voltage to the platen assembly, generating a plasma within the process chamber, monitoring a voltage difference between the platen assembly and the process chamber, during the etch process, and attenuating or extinguishing the plasma to prevent further etching once a threshold monitored voltage is reached.

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Cardiff, United Kingdom

Roland Mumford