A delta-doped amorphous silicon thin-film transistor with high mobility and stability

Ultrathin doped layers, known as delta-doped layers, were introduced within the intrinsic amorphous silicon (a-Si) active layer to fabricate hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) with enhanced field-effect mobility. The performance of the delta-doped a-Si:H TFTs depended on the phosphine (PH 3 ) flow rate and the distance from the n + a-Si to the deltadoping layer. The delta-doped a-Si:H TFTs fabricated using a commercial manufacturing process exhibited an enhanced field-effect mobility of approximately ∼0.23 cm 2 /Vs (compared to a conventional a-Si:H TFT with 0.15 cm 2 /Vs) and a desirable stability under a bias-temperature stress test.