Plasma-based method for delayering of circuits
| DWPI Title: Removing material from die using plasma-based process involves providing die including device layer, conductive layer including first metal layer in proximity to back-side surface, and second metal layer |
| Abstract: The present invention relates to methods of delayering a semiconductor integrated circuit die or wafer. In at least one aspect, the method includes exposing a die or wafer to plasma of an etching gas and detecting exposure of one or more metal layers within the die. In one aspect of the invention, the plasma of the etching gas is non-selective and removes all materials in a layer at about the same rate. In another aspect of the invention, two different plasmas of corresponding etching gases are employed with each plasma of the etching gas being selective, thus necessitating the sequential use of both plasmas of corresponding etching gases to remove all materials in a layer. |
| Use: Method for removing material from die using plasma-based process. |
| Advantage: The method removes material with atomic layer precision and/or provides front-side delayering applications. It has the ability to uniformly delayer entire die or entire wafers, without the need to stitch field of view (FOV) using appropriate chemistry in a plasma etch tool. |
| Novelty: Removing material from die (100) using plasma-based process involves providing a die, where the die includes a device layer (102), a conductive layer and a contact layer (104). The portion of a front-side surface of the contact layer is etched to expose a portion of the metal layer to provide an etched die. The etched die is exposed to two inductively coupled plasma employing two etching gases, where one of the etching gas includes hydrocarbon, halogen, fluorocarbon, carbonyl and acetate. The exposure of another metal layer is detected to provide a delayered die. |
| Filed: 2/14/2023 |
| Application Number: US18109651A |
| Tech ID: SD 14775.2 |
| 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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