Method of manufacturing thin film transistor
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorHisashi Ohtani
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Abstract
The object of the present invention is to form a low-concentration impurity region with good accuracy in a top gate type TFT. Phosphorus is added to a semiconductor layer by using a pattern made of a conductive film as a mask to form an N-type impurity region in a self-alignment manner. A positive photoresist is applied to a substrate so as to cover the pattern and then is exposed to light applied to the back of the substrate and then is developed, whereby a photoresist 110 is formed. The pattern is etched by using the photoresist pattern as an etching mask to form a gate electrode. A channel forming region, a source region, a drain region, and low-concentration impurity regions, are formed in the semiconductor layer in a self-alignment manner by using the gate electrode as a doping mask.
Claims10
A method for manufacturing an organic electroluminesence display device having a thin film transistor at a pixel comprising the steps of:
- forming a semiconductor layer over a transparent substrate;
- forming a gate insulating film on said semiconductor layer;
- forming a conductive film over said gate insulating film;
- patterning said conductive film thereby forming a pattern comprising said conductive film;
- adding an impurity which will be donor or acceptor into said semiconductor layer by using said pattern comprising said conductive film as a mask;
- applying a photoresist covering said pattern comprising said conductive film;
- exposing said photoresist to a light irradiated from back of said transparent substrate and developing thereby forming a photoresist pattern that is narrower than said pattern comprising said conductive film;
- and
- forming a gate electrode by patterning said pattern comprising said conductive film by using said photoresist pattern as a mask.
A method according to 1, wherein said display device is incorporated into a semiconductor device selected from a group consisting of a computer, a projector, a projecting TV, a head mounted display, a video camera, a digital still camera, a car navigation system, a notebook type personal computer, a mobile telephone or an electronic notebook.
A method for forming an organic electroluminesence display device having a thin film transistor at a pixel comprising the steps of:
- forming a semiconductor layer over a transparent substrate:
- forming a gate insulating film on said semiconductor layer;
- forming a conductive film over said gate insulating film;
- patterning said conductive film thereby forming a pattern comprising said conductive film;
- adding an impurity which will be donor or acceptor into said semiconductor layer by using said pattern comprising said conductive film as a mask;
- applying a photoresist covering said pattern comprising said conductive film;
- exposing said photoresist to a light irradiated from back of said transparent substrate and developing thereby forming a photoresist pattern that is narrower than said pattern comprising said conductive film;
- forming a gate electrode by patterning said pattern comprising said conductive film by using said gate electrode as a mask;
- patterning said gate insulating film by using said gate electrode as a mask;
- and
- adding an impurity which will be donor or acceptor into said semiconductor layer by using said gate electrode as a mask.
A method for manufacturing an active matrix organic electroluminesence display device having a thin film transistor at a pixel comprising the steps of:
- forming a semiconductor layer over a transparent substrate:
- forming a gate insulating film in contact with said semiconductor layer:
- forming a conductive film over said gate insulating film;
- patterning said conductive film thereby forming a pattern comprising said conductive film;
- adding an impurity which will be donor or acceptor into said semiconductor layer by using said pattern comprising said conductive film as a mask;
- applying a photoresist covering said pattern comprising said conductive film;
- exposing said photoresist to a light irradiated from back of said transparent substrate and developing thereby forming a photoresist pattern that is narrower than said pattern comprising said conductive film;
- forming a gate electrode by patterning said pattern comprising said conductive film by using said photoresist pattern as a mask;
- forming a planarizing film over said gate electrode;
- and
- forming a pixel electrode over said planarizing film.
A method according to 6, wherein said display device is incorporated into a semiconductor device selected from a group consisting of a computer, a projector, a projecting TV, a head mounted display, a video camera, a digital still camera, a car navigation system, a notebook type personal computer, a mobile telephone or an electronic notebook.
A method for manufacturing an active matrix organic electroluminesence display device having a thin film transistor at a pixel comprising the steps of:
- forming a semiconductor layer over a transparent substrate;
- forming a gate insulating film on said semiconductor layer;
- forming a conductive film over said gate insulating film;
- patterning said conductive film thereby forming a pattern comprising said conductive film;
- applying a photoresist covering said pattern comprising said conductive film;
- exposing said photoresist to a light irradiated from back of said transparent substrate and developing thereby forming a photoresist pattern that is narrower than said pattern comprising said conductive film;
- adding an impurity which will be donor or acceptor into said semiconductor layer by using said photoresist pattern as a mask;
- forming a gate electrode by patterning said pattern by using said photoresist pattern as a mask;
- patterning said gate insulating film by using said gate electrode as a mask;
- adding an impurity which will be donor or acceptor into said semiconductor layer by using said gate electrode as a mask;
- forming a planarizing film over said gate electrode;
- and
- forming a pixel electrode over said planarizing film.
Dependencies are inferred from the claim text.