Method and apparatus for identifying high metal content on a semiconductor surface
AssigneeChartered Semiconductor Manufacturing Ltd.
InventorsSik On Kong, Tsui Ping Chu
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Abstract
A new method and apparatus for detecting and measuring the level of metal present on the surface of a substrate is achieved. Energy, in the form of rf or light or microwave energy, is directed at the surface of a wafer, the reflected energy or the energy that passes through the semiconductor substrate is captured and analyzed for energy level and/or frequency content. Based on this analysis conclusions can be drawn regarding presence and type of metal on the surface of the wafer. Furthermore, by inclusion of metal within the resonating circuit of an rf generator changes the frequency of the vibration and therefore detects the presence of metal.
Claims15
A method for identifying high metal surface content substrate comprising:
- providing a semiconductor substrate;
- providing a source of microwave radiation;
- providing a first and second microwave energy measurement apparatus;
- exposing said semiconductor substrate to microwave radiation provided by the source of microwave radiation;
- capturing, by said first microwave energy measurement apparatus, microwave energy reflected by said semiconductor substrate, thereby driving said first microwave energy measurement apparatus;
- capturing, by said second microwave energy measurement apparatus, microwave energy passed through said semiconductor substrate, thereby driving said second microwave energy measurement apparatus;
- measuring said reflected microwave energy;
- measuring said passed through microwave energy;
- comparing said reflected microwave energy with said passed through microwave energy;
- and
- initiating intervention, by raising a visual or audible alarm invoking human or automatic intervention, if said reflected microwave energy exceeds said passed through microwave energy.
An apparatus for identifying high metal surface content substrate comprising:
- a source of microwave radiation;
- a first and second microwave energy measurement apparatus;
- a means for exposing a semiconductor substrate to microwave radiation provided by the source of microwave radiation;
- a means for capturing, by said first microwave energy measurement apparatus, microwave energy reflected by said semiconductor substrate thereby driving said first microwave energy measurement apparatus;
- a means for capturing, by said second microwave energy measurement apparatus, microwave energy passed through said semiconductor substrate thereby driving said second microwave energy measurement apparatus;
- a means for measuring said reflected microwave energy;
- a means for measuring said passed through microwave energy;
- a means for comparing said reflected microwave energy with said passed through microwave energy;
- and
- a means for initiating intervention, by raising a visual or audible alarm invoking human or automatic intervention, if said reflected microwave energy exceeds said passed through microwave energy.
Dependencies are inferred from the claim text.