Tft electronic devices and their manufacture

摘要

An electronic device ( 70 ) comprises a thin film transistor (TFT) ( 9,59 ), the TFT including a channel ( 16 ) defined in a layer of polycrystalline semiconductor material ( 10,48 ). The polycrystalline semiconductor material is produced by crystallising amorphous semiconductor material ( 2 ) using metal atoms ( 6 ) to promote the crystallisation process. The polycrystalline semiconductor material ( 10 ) includes an average concentration of metal atoms in the range 1.3x10¹⁸ to 7.5x10¹⁸ atoms/cm³. This enables polycrystalline semiconductor TFTs to be formed with leakage properties acceptable for use in active matrix displays using a metal induced crystallisation process of duration significantly less that previously thought necessary. Furthermore, this process duration reduction facilitates the reliable fabrication of poly-Si TFTs having bottom gates formed of metal.