| 摘要 |
A titanium-tungsten (T2-W) barrier layer (70) is provided between a signal line and an N-type silicon region in a NPN transistor device having an emitter contact window (62) exposed to N-type silicon, a collector contact window (60) exposed to N-type silicon and a further contact window (64) having a layer (35, Fig. 7) of silicon dioxide over P-type silicon, by depositing a layer (70) of an alloy of titanium-tungsten on the surface of the processed semiconductor wafer and etching the titanium-tungsten layer out of the further contact window (64). The silicon dioxide layer (35, Fig. 7) is then etched out of the further contact window to expose the P-type silicon. A metallisation layer of aluminium is then deposited on the semiconductor wafer and undesired portions are etched away using conductor interconnect photolithography to define signal lines (100, 102, 104). Those portions of the titanium-tungsten layer not covered by the signal lines are etched away so that the titanium-tungsten layer provides barrier metal between the signal lines and the N-type silicon of the emitter and collector contact windows so that the signal lines connect directly to the further contact window. Alternatively the titanium-tungsten layer remains only in the emitter contact window. <IMAGE> |
