摘要 |
The durable mask includes a polyimide layer formed over a portion of a semiconductor substrate to be masked. A heavy metal layer is then formed over the polyimide layer. An adhesion layer is formed between the polyimide layer and the heavy metal layer to insure adhesion of the heavy metal layer to the polyimide layer. The durable mask may mask, for example, a heterojunction bipolar transistor formed in the semiconductor substrate prior to an ion implantation process. Furthermore, the mask is removed from the substrate by eliminating the adhesion between the mask and substrate or by dissolving the polyimide layer.
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