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Patent Issued for Manufacturing Method for Display Device Having a Plurality of Thin Film Transistors and Display Device Formed Thereby

February 26, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventor Ko, Moo-Soon (Yongin, KR), filed on March 8, 2012, was published online on February 11, 2014.

The patent's assignee for patent number 8647931 is Samsung Display Co., Ltd. (Yongin, Gyeonggi-Do, KR).

News editors obtained the following quote from the background information supplied by the inventors: "An embodiment of the present invention relates to a manufacturing method of a thin film transistor.

"Flat panel displays such as, organic light emitting diode (OLED) displays and liquid crystal displays (LCD) include thin film transistors for driving. For smooth operation of these devices, the thin film transistors need to be manufactured to have good quality.

"In manufacturing process of the display devices, when forming the thin film transistors, a photoresist is used as a mask for ion injection process.

"However, when using such photoresist, unnecessary mobile ions can be moved into the semiconductor layer from the photoresist, and negatively influence to the operation of thin film transistors.

"Also, a process for removing the used photoresist mask can make productivity low as the number of processes increases, and the thin film transistors may be contaminated during a cleaning process following removal of the photoresist.

"The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventor's summary information for this patent: "An embodiment of the present invention provides a manufacturing method of a thin film transistor that forms the thin film transistor without usage of a photoresist mask when injecting ions for forming the thin film transistor, and a display device including the thin film transistor manufactured thereby.

"A manufacturing method of a thin film transistor according to an embodiment of the present invention includes: forming semiconductor layers for a plurality of thin film transistors over a substrate; forming an insulating layer covering the semiconductor layers over the substrate; forming a metal layer over the insulating layer; patterning the metal layer to form mask patterns, each of which corresponds to one of the semiconductor layers; doping first ions using a first mask pattern among the mask patterns into a first semiconductor layer among the semiconductor layers to simultaneously form a source region/a drain region and an active region of a first thin film transistor; and doping second ions using a second mask pattern among the mask patterns into a second semiconductor layer among the semiconductor layers to form a source region and a drain region of a second thin film transistor.

"When forming the source region/drain region and the active region of the first thin film transistor, the second semiconductor layer and the second mask pattern may be covered by a photoresist.

"When forming the source region and the drain region of the second thin film transistor, the first semiconductor layer and the first mask pattern may be covered by a photoresist.

"The first mask pattern may have a thickness substantially different from that of and the second mask pattern.

"The thickness of the first mask pattern may be smaller than the thickness of the second mask pattern.

"The first mask pattern and the second mask pattern may be formed by half-tone exposure.

"The first mask pattern and the second mask pattern may be respectively formed as a gate electrode of the first thin film transistor and a gate electrode of the second thin film transistor, respectively.

"The first thin film transistor may be an NMOS thin film transistor and the second thin film transistor may be a PMOS thin film transistor.

"A display device according to an embodiment of the present invention includes a thin film transistor manufactured by the above manufacturing method of the above thin film transistor.

"The display device may be an organic light emitting diode (OLED) display or a liquid crystal display (LCD).

"According to an embodiment of the present invention, a metal layer is used as masks when injecting the ions for forming the thin film transistor without usage of a photoresist such that unnecessary movement of ions into the semiconductor layer may be prevented, thereby manufacturing a thin film transistors having good quality. Accordingly, the display device including the thin film transistors manufactured according to the present embodiment stably operate such that good quality images may be realized by the thin film transistors.

"Also, the threshold voltage (Vth) may be precisely controlled by the effect of the channel doping through the active region doping process of the thin film transistor.

"Further, forming the active region and the source/drain region for the thin film transistor may be accomplished through a single process, and the productivity may be improved for the process simplification.

"In addition, the thin film transistor and the wire have different thicknesses such that resistance of the wire is not decreased."

For additional information on this patent, see: Ko, Moo-Soon. Manufacturing Method for Display Device Having a Plurality of Thin Film Transistors and Display Device Formed Thereby. U.S. Patent Number 8647931, filed March 8, 2012, and published online on February 11, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=64&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3155&f=G&l=50&co1=AND&d=PTXT&s1=20140211.PD.&OS=ISD/20140211&RS=ISD/20140211

Keywords for this news article include: Electronics, Semiconductor, Light-emitting Diode, Samsung Display Co. Ltd..

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Source: Electronics Newsweekly


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