Enhanced microfabrication using electrochemical techniques
| DWPI Title: Method for subtractively processing layer of etchable material formed over electrically conductive surface region of workpiece, involves measuring electrical signal in electrochemical circuit, terminating etching when electrochemical signal satisfies criterion indicating that etching is complete |
| Abstract: A method is provided for subtractively processing a layer of etchable material formed over an electrically conductive surface region of a workpiece. The workpiece is immersed in a liquid solution, generally but not exclusively a conductive solution, that comprises an etchant for the etchable material, so that etching of the etchable material is initiated. An electric circuit is connected to include a control electrode, a reference electrode, and the electrically conductive surface region of the workpiece. The electric circuit is used to monitor the development process dynamically at each of a plurality of intervals during the etching. The etching is terminated when the electrochemical signal satisfies a criterion indicating that the etching is complete. |
| Use: Method for subtractively processing a layer of etchable material formed over an electrically conductive surface region of a workpiece i.e. photoresist. |
| Advantage: The method can potentially detect the endpoint with high accuracy, and it can be automated. It provides improvements in quality, throughput, reliability, economy, and consistency of fabricated microelectronic devices. |
| Novelty: Processing layer of etchable material formed an electrically conductive surface region of workpiece involves connecting workpiece in an electrochemical circuit; immersing portion of workpiece in a liquid solution that comprises an etchant for the etchable material, so that etching of the etchable material is initiated; monitoring the etching of the etchable material at each of a multiple of intervals between the initiation of the etching and endpoint of etching, where dynamic monitoring comprises measuring an electrical signal in electrochemical circuit; performing multiple of rinse cycles, workpiece is rinsed during each of the rinse cycles; measuring electrical signal in electrochemical circuit during each rinse cycle for dynamic monitoring of etching, measurement of electrical signal for dynamic monitoring being performed during rinsing but not during etching; and terminating etching when electrochemical signal satisfies criterion indicating that endpoint has been reached. |
| Filed: 1/10/2019 |
| Application Number: US16244501A |
| Tech ID: SD 14347.1 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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