Formation of Single-layer Al-alloy Interconnection for Source and Drain of a-Si TFT using One-wet-one-dry Etching with Four-mask Process

摘要

Single layer Al-alloy interconnection far source and drain of amorphous Si (a-Si) thin film transistor (TFT) is demonstrated by direct-contact technology with no barrier metals at the interfaces with both ITO and a-Si. Thermally stable contacts were formed on a-Si with a buried nitridation layer while maintaining the contact resistivity as low as 0. 1Ωcm{sup}2. Excessive interdiffusion between the Al-alloy electrode and a-Si that can degrade TFT characteristics was suppressed by the nitridation layer. The Al-alloy direct contact technology, combined with one-wet-one-dry etching with four-mask process, drastically simplifies the TFT fabrication process and contributes to cost reduction of a-Si TFT LCD.