Method for manufacturing display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsHidekazu Miyairi, Yasuhiro Jinbo, Kosei Nei
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Abstract
A method for manufacturing display devices including thin film transistors with high reliability in a high yield is provided. A gate insulating film is formed over a gate electrode; a microcrystalline semiconductor is formed over the gate insulating film; the microcrystalline semiconductor film is irradiated with a laser beam from the surface side thereof, whereby the crystallinity of the microcrystalline semiconductor film is improved. Then, a thin film transistor is formed using the microcrystalline semiconductor film whose crystallinity is improved. Further, a display device including the thin film transistor is manufactured.
Claims24
A method for manufacturing a display device, comprising the steps of:
- forming a gate electrode over a substrate;
- forming a gate insulating film over the substrate and over the gate electrode;
- forming a microcrystalline semiconductor film over the gate insulating film;
- irradiating the microcrystalline semiconductor film with a laser beam;
- forming a buffer layer over the microcrystalline semiconductor film, after the step of irradiating;
- forming a impurity semiconductor film over the buffer layer, to which an impurity element which imparts one conductivity type is added;
- forming a source region and a drain region by selectively etching the impurity semiconductor film;
- forming a source electrode over the source region, and a drain electrode over the drain region;
- and
- forming a pixel electrode in contact with one of the source electrode and the drain electrode.
A method for manufacturing a display device, comprising the steps of:
- forming a gate electrode over a substrate;
- forming a gate insulating film over the substrate and over the gate electrode;
- forming a microcrystalline semiconductor film over the gate insulating film;
- irradiating the microcrystalline semiconductor film with a laser beam;
- forming a buffer layer over the microcrystalline semiconductor film, after the step of irradiating;
- forming a impurity semiconductor film over the buffer layer, to which an impurity element which imparts one conductivity type is added;
- forming a source region and a drain region by selectively etching the impurity semiconductor film;
- selectively etching the buffer layer and the microcrystalline semiconductor film after the step of forming the source region and the drain region;
- forming a source electrode over the source region, and a drain electrode over the drain region, after the step of selectively etching the buffer layer and the microcrystalline semiconductor film;
- and
- forming a pixel electrode in contact with one of the source electrode and the drain electrode.
A method for manufacturing a display device, comprising the steps of:
- forming a gate electrode over a substrate;
- forming a gate insulating film over the substrate and over the gate electrode;
- forming a microcrystalline semiconductor film over the gate insulating film;
- irradiating the microcrystalline semiconductor film with a laser beam;
- forming a buffer layer over the microcrystalline semiconductor film, after the step of irradiating;
- forming a impurity semiconductor film over the buffer layer, to which an impurity element which imparts one conductivity type is added;
- forming a conductive film over the impurity semiconductor film;
- forming a first resist mask over the conductive film, by a photolithography process using a multi-tone photomask;
- selectively etching the conductive film, the buffer layer and the microcrystalline semiconductor film;
- forming a second resist mask by ashing the first resist mask;
- forming a source electrode and a drain electrode by selectively etching the conductive film using the second resist mask;
- forming a source region under the source electrode and a drain region under the drain electrode, by selectively etching the impurity semiconductor film using the second resist mask;
- and
- forming a pixel electrode in contact with one of the source electrode and the drain electrode.
Dependencies are inferred from the claim text.