| 摘要 |
PURPOSE:To suppress the burying of an alignment key by the deposition of high-temperature aluminum sputter, concerning a alignment key formation method. CONSTITUTION:A first BPSG interlayer film 2, a polycrystalline silicon film 3, and a second BPSG interlayer film 4 are formed in the alignment key area made at boring of a contact hole, and with the resist 5 for boring the contact hole as a mask, a second BPSG interlayer film 4 is removed by dry etching. And, the polycrystalline silicon film 3 is removed to retreat in lateral direction from the second BPSG interlayer film 4 under the condition of anisotropic etching, and then the first BPSG interlayer film 2 is removed. Hereby, the Ti/TiN/Ti film formed before deposition of high-temperature aluminum becomes discontinuous by providing a recess at the sidewall in the alignment key area made at boring of the contact hole, the inflow of aluminum into an alignment key is suppressed, and an alignment error is prevented. |
