Non-classical polycrystalline silicon thin-film transistor with embedded block-oxide for suppressing the short channel effect

In this paper, a polycrystalline silicon (polysilicon) thin-film transistor with a block oxide enclosing body, BTFT, is fabricated and investigated. By utilizing the block-oxide structure of thin-film transistors, the BTFT is shown to suppress the short channel effect. This proposed structure is formed by burying self-aligned oxide spacers along the sidewalls of the source and drain junctions, which reduces the P-N junction area, thereby reducing the junction capacitance and leakage current. Measurements demonstrate that the BTFT eliminates the punch-through effect even down to gate lengths of 1.5 νm, whereas the conventional TFT suffers serious short channel effects at this gate length.