Plasma-based method for delayering of circuits
| DWPI Title: Performing plasma based process for delayering of circuits, involves providing die, etching portion of front-side surface of contact layer to expose portion of second metal layer, thus providing etched die, exposing etched die to first inductively coupled plasma employing first etching gas |
| 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 performing a plasma based process for delayering of circuits. |
| Advantage: The method enables to remove material with atomic layer precision and/or to provide front-side delayering applications. The methods provide a die having removed material (e.g., as in an etched die or a delayered die). The method provides 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: Performing a plasma based process involves providing a die. At least a portion of a front-side surface of the contact layer is etched to expose at least a portion of the second metal layer, thus providing an etched die. The etched die is exposed to a first inductively coupled plasma employing a first etching gas. The etched die is exposed to a second inductively coupled plasma employing a second etching gas, the second inductively coupled plasma employing the second etching gas producing a second plasma etch, the second plasma etch chemically and physically removing at least a portion of the set of first vias and a portion of the first interlayer dielectric, the second plasma etch being non-selective, the second plasma etch adapted to remove the set of first vias and the first interlayer dielectric at about the same rate. The exposure of the first metal layer is detected, thus providing a delayered die. |
| Filed: 7/29/2020 |
| Application Number: US16941676A |
| Tech ID: SD 14775.1 |
| 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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