Process for preparing a polycrystalline semiconductor thin film transistor
AssigneeAsahi Glass Company, Limited
InventorsKunio Masumo, Masanori Yuki
Life of this patent
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Abstract
A process for preparing a polycrystalline semiconductor thin film transistor wherein a non-singlecrystalline semiconductor formed on a transparent insulating substrate is annealed by laser beams, such process comprising forming a gate insulation layer and a gate electrode on the non-singlecrystalline semiconductor; implanting impurity ions into a source-drain region of the semiconductor wherein the gate electrode is used as a mask, and irradiating laser beams from the rear surface side of the transparent insulating substrate to thereby polycrystallize the non-singlecrystalline semiconductor under the gate electrode or improve the crystallinity of the semiconductor without causing the non-singlecrystalline semiconductor in a completely molten state.
Claims5
A process for preparing a polycrystalline semiconductor thin film transistor, comprising the steps of:
- forming a non-singlecrystalline semiconductor layer formed of amorphous silicon and having a thickness of 10-500 nm on a front surface side of a transparent substrate;
- forming a gate insulation layer on the non-singlecrystalline semiconductor layer;
- forming a gate electrode of non-singlecrystalline semiconductor on the gate insulation layer at a channel region;
- implanting impurity ions into the gate electrode and a source-drain region of said non-singlecrystalline semiconductor layer formed of amorphous silicon, wherein the gate electrode of semiconductor is used as a mask;
- irradiating laser beams so that simultaneously the non-singlecrystalline semiconductor at the channel region is polycrystallized, the non-singlecrystalline semiconductor at the source and drain region is polycrystallized, said impurity ions implanted into the non-singlecrystalline semiconductor at the source-drain region are activated, and
- said impurity ions implanted into the gate electrode are activated and the non-singlecrystalline semiconductor of the gate electrode is polycrystallized, without causing said non-singlecrystalline semiconductor layer to reach a molten state.
Dependencies are inferred from the claim text.