| 摘要 |
A flat panel display or other large-area electronic device comprises at least one TFT (T1; T2) having a crystalline channel region (1) and amorphous edge regions (13) adjacent sidewalls (12) of the TFT island (11). The TFT is fabricated by steps which include: (a) depositing on substrate (10) a thin film (11') of amorphous semiconductor material to provide the semiconductor material, (b) removing areas of the thin film (11') to form the side walls (12a, 12b) of each island (11), (c) forming a masking pattern (20) over the edge regions (13a, 13b) preferably on an insulating film (22), and (d) directing a laser or other energy beam (50) towards the islands (11) and the masking pattern (20) to crystallise the un-masked semiconductor material for the crystalline channel region (1), while retaining amorphous semiconductor material adjacent the side walls (12a, 12b) where the edge regions (13a, 13b) are masked from the energy beam (50) by the masking pattern (20). The resulting device structure has e.g polycrystalline TFTs (T1, T2) with low off-state leakage currents as a result of the amorphous material properties kept for the edge regions (13a) particularly where crossed by the insulated gate (4). The substrate (10) may be of polymer material which also is masked from the beam (50) by the masking pattern (20). |
