Thin film transistor having a short channel formed by using an exposure mask with slits
AssigneeLG.Philips LCD Co., Ltd.
InventorKwang-Jo Hwang
Life of this patent
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Abstract
A mask containing apertures therein which is used for fabricating a channel of a thin film transistor (TFT), wherein the pixel charging time for a TFT in a high-resolution liquid crystal display (LCD) device is reduced by minimizing the length of the channel in the TFT when active region is made of amorphous silicon. The length of the channel can be minimized by exposing light through the apertures is an exposure mask when forming the channel.
Claims20
A method for fabricating a thin film transistor (TFT) for a liquid crystal display(LCD) device comprising the steps of:
- forming a gate electrode on a glass substrate and forming an active region above the gate electrode;
- forming a channel region by depositing a metal onto the active region, thereby forming a source and a drain on each end of the active region by patterning the metal using a photolithography process and etching an upper portion of the active region between the source and drain;
- and
- forming a pixel electrode which electrically contacts the drain by depositing a passivation layer on the upper surface of the structure and exposing a part of the drain by forming a contact hole through the passivation layer,
- wherein the photolithography process employs a silt type mask having a slit structure which forms the channel region having a length of 1 μm to 4 μm.
A method for fabricating a thin film transistor (TFT) for a liquid crystal display (LCD) device the steps of:
- forming a gate electrode on a substrate;
- forming an active region above the gate electrode;
- forming a source and a drain above the active region;
- forming a channel at the active region between the source and the drain by exposing a portion of the active region with light energy passing through a slit-type mask having a channel length less than 4 μm;
- and
- forming a pixel electrode electrically connected with the drain so that charge current from the gate electrode can be supplied to a pixel via the channel.
A thin film transistor (TFT) for a liquid crystal display (LCD) device comprising:
- a substrate with a gate electrode thereon;
- an active region formed above the gate electrode;
- a source and a drain formed above the gate electrode and at the end portions of the active region;
- a channel formed in the active region, said channel having a length of not more than 4 μm;
- and
- a pixel electrode electrically connected with the drain so that charge current from the gate electrode can be supplied to the pixel via the channel.
A thin film transistor (TFT) for a liquid crystal display (LCD) device which comprises:
- a substrate with a gate electrode thereon;
- an active region formed above the gate electrode;
- a source and a drain formed above the gate electrode and at the end portions of the active region;
- a channel formed in the active region, said channel having a shortened and defined length produced by a controlled transmission of light or energy irradiated onto the channel region;
- and
- a pixel electrode electrically connected with the drain so that charge current from the gate electrode can be supplied to the pixel via the channel.
A liquid crystal display (LCD) device containing a thin film transistor (TFT) which comprises:
- a substrate with a gate electrode thereon;
- an active region formed above the gate electrode;
- a source and a drain formed above the gate electrode and at the end portions of the active region;
- a channel formed in the active region, said channel having a length of not more than 4 μm;
- and
- a pixel electrode electrically connected with the drain so that charge current from the gate electrode can be supplied to the pixel via the channel.
A method for fabricating a thin film transistor (TFT) for a liquid crystal display (LCD) device the steps of:
- forming a gate electrode on substrate;
- forming an active region above the gate electrode;
- forming a source and a drain above the active region;
- forming a channel at the active region between the source and the drain by exposing a portion of the active region with light energy passing through apertures in a mask which are effective in shortening the length of the channel by providing a controlled transmission of light or energy radiation onto the channel;
- and
- forming a pixel electrode electrically connected with the drain so that charge current from the gate electrode can be supplied to the pixel via the channel.
Dependencies are inferred from the claim text.