The disclosure relates to display technical field, specifically a low temperature polycrystalline silicon thin film transistor and manufacturing thereof.
Thin Film Transistor (TFT) is used to as switch in liquid crystal display device, the property of TFT includes lower power consumption, smaller size and lower driving voltage, and is suitable for computer, laptop and any other display device. In the present liquid crystal display device, active layer of thin film transistor mainly use amorphous silicon (a-Si), but thin film transistor using amorphous silicon as active layer has very low mobility and is difficult to meet the driving requirement of peripheral circuit; hence, Low Temperature Poly-silicon instead of amorphous silicon technology emerged.
The mobility of Low temperature polycrystalline silicon may up to 100 cm2/V·S to meet the driving requirement of peripheral circuit, and is more suitable than amorphous silicon to use in the active layer of thin film transistor so that it is more compact than amorphous silicon thin film transistor. The principle of manufacturing structure of Low temperature polycrystalline silicon thin film transistor is that excimer laser is used to be a heat source to project on an amorphous silicon structure of a glass substrate, and then the amorphous silicon structure substrate is turned into a polycrystalline silicon structure after absorbing energy of excimer laser.
The present technical process includes mainly traditional Excimer Laser Annel (ELA) method without using mask and Sequential Lateral Solidification (SLS) with using mask to control laser irradiation region. By applying traditional ELA method, grain size of low temperature polycrystalline silicon generally is under 0.1 μm; by applying SLS method, crystallization procedure is induced from end of the irradiation region to inside, and then crystallization of the center of the irradiation portion is executed. Obviously, grain size of the polycrystalline silicon manufactured by above two methods are smaller to limit the practical application of polycrystalline silicon.
In order to overcome the insufficient of present technology, purpose of the disclosure is to provide a low temperature polycrystalline silicon thin film transistor and manufacturing thereof; finally, larger grain size of polycrystalline silicon is manufactured by the method and improves electron mobility of thin film transistor to meet the driving demand of peripheral circuits.
The disclosure provides a low temperature polycrystalline silicon thin film transistor, and the thin film transistor includes:
Wherein, the semiconductor layer is a low temperature poly silicon layer, and a reflective layer and/or an insulation layer are disposed between the buffer layer and the semiconductor layer.
Further, the low temperature polycrystalline silicon thin film transistor comprises a pixel thin film transistor and a driving thin film transistor, the substrate comprises a pixel region and a peripheral driving region, the pixel region is used for forming the pixel thin film transistor, and the peripheral driving region is used for forming the driving thin film transistor;
Further, the pixel thin film transistor comprises: a substrate inside the pixel region, and all the buffer layer, the semiconductor layer, the gate insulation layer, gates, the dielectric layer and the passivation layer formed sequentially from the top on the substrate inside the pixel region; the first contact hole and the second contact hole are formed respectively inside the passivation layer, the dielectric layer and the gate insulation layer, and the sources and the drains are formed respectively on the first contact hole and the second contact hole.
Further, a grain size of the semiconductor layer located inside the driving thin film transistor is larger than a grain size of the semiconductor layer located inside the pixel thin film transistor.
Further, the buffer layer comprises a first buffer layer formed on the substrate, the reflective layer is formed on the first buffer layer, a second buffer is formed on the first buffer layer and the reflective layer, the reflective layer is covered inside the second buffer layer, and the semiconductor layer is formed on the second buffer layer.
Preferably, materials of the reflective layer are one or more combinations from the group of Mo, Al, AlNd, Cr, Cu, W, Ta or Ti, preferably material of the reflective layer is Mo, and the reflective layer is metal Mo layer.
Preferably, materials of the first buffer layer and the second buffer layer are one or two combinations of Silicon nitride and Silica.
Preferably, the first buffer layer is Silicon nitride layer, and the second buffer layer is Silica layer.
Further, the buffer layer comprises a first buffer layer and a second buffer layer is formed sequentially on the substrate, the insulation layer is formed on the second buffer layer, and the semiconductor layer is formed on the second buffer layer and the insulation layer.
Further, the insulation layer is alumina layer.
Preferably, materials of the first buffer layer and the second buffer layer are one or two combinations of Silicon nitride and Silica.
Preferably, the first buffer layer is Silicon nitride layer, and the second buffer layer is Silica layer.
Preferably, the substrate is glass substrate.
Besides, the disclosure also provides a manufacturing method for low temperature polycrystalline silicon thin film transistor comprising following steps:
Preferably, a first buffer layer is deposited on the substrate, the reflective layer is deposited on the first buffer layer, and by applying photolithography and etching technology, a pattern is defined on the reflective layer; a second buffer layer is deposited on the first buffer layer and the reflective layer, and the reflective layer is covered into the second buffer layer; the amorphous silicon layer is deposited on the second buffer layer, and then by applying laser radiation, the amorphous silicon layer is turned into a polycrystalline silicon layer in order to obtain the semiconductor layer.
Preferably, materials of the reflective layer are one or more combination from the group of Mo, Al, AlNd, Cr, Cu, W, Ta or Ti, preferably material of the reflective layer is Mo, and the reflective layer is metal Mo layer.
Preferably, materials of the first buffer layer and the second buffer layer are one or two combinations of Silicon nitride and Silica.
Preferably, the first buffer layer is Silicon nitride layer, and the second buffer layer is Silica layer.
Preferably, a first buffer layer and a second buffer layer are formed sequentially on the substrate by depositing; the insulation layer is deposited on the second buffer layer, and by applying photolithography and etching technology, a pattern is defined on the insulation layer; the amorphous silicon layer is deposited on the second buffer layer and the insulation layer, and then by applying laser radiation, the amorphous silicon layer is turned into a polycrystalline silicon layer in order to obtain the semiconductor layer.
Further, the insulation layer is alumina layer.
Preferably, materials of the first buffer layer and the second buffer layer are one or two combinations of Silicon nitride and Silica.
Preferably, the first buffer layer is Silicon nitride layer, and the second buffer layer is Silica layer.
Optionally, the method for forming each layers structure of low temperature thin film transistor Chemical vapor deposition or Physical vapor deposition.
Optionally, in the step of “forming an amorphous silicon layer on the buffer layer, the reflective layer and/or the insulation layer, performing laser radiation to turn the amorphous silicon layer into a polycrystalline silicon layer, and the polycrystalline silicon layer is a semiconductor layer,” the method of “performing laser radiation” is excimer laser anneal (ELA) or Solid Phase Crystallization (SPC).”
Preferably, the substrate is glass substrate.
Compare with present technology, the benefit of the present disclosure is as following:
In the disclosure, through setting the reflective layer and/or the insulation layer under the amorphous silicon layer, the laser radiation returns to the amorphous silicon layer from the reflective layer again after being through the amorphous silicon layer to enlarger the grain size or by insulation effect of the insulation layer to extend the time of crystallization of the amorphous silicon layer, and then the larger size of polycrystalline silicon grains are obtained. When the reflective layer and/or the insulation layer are only located inside the peripheral driving region, a polycrystalline silicon grain size by laser radiation is larger than a polycrystalline silicon grain size of the pixel region, and larger grain size may contribute better electron mobility in the peripheral driving region and thus contribute the driving efficiency in the peripheral driving region.
The embodiment provides a low temperature polycrystalline silicon thin film transistor, and the thin film transistor includes a pixel thin film transistor and a driving thin film transistor; the manufacturing method for the low temperature polycrystalline silicon thin film transistor is as follows:
As shown in
Then, as shown in
Then, as shown in
Then, as shown in
Then, a conductive layer is deposited on the first contact holes 91, 93 and the second contact holes 92, 94 by applying CVD method, and sources 95, 97 and drains 96, 98 are defined as shown in
In the disclosure, photolithography is a technology that the particular portion of film of the wafer surface is eliminated by series of manufacturing steps. After that, a micro pattern structure of film is retained on the wave surface. Through photolithography technics process, the particular portion is finally retained on the wafer. The technology is a common technics art in the area of manufacturing thin film, and the descriptions are not repeated here.
Etching technology means that materials are removed by applying chemical reaction or physical shock. The technology is a common technics art in the area of manufacturing thin film, and the descriptions are not repeated here.
The embodiment provides a low temperature polycrystalline silicon thin film transistor, and the thin film transistor includes a pixel thin film transistor and a driving thin film transistor; the manufacturing method for the low temperature polycrystalline silicon thin film transistor is as follows: As shown in
Then, as shown in
Then, as shown in
Then, as shown in
Then, a conductive layer is deposited on the first contact holes 91, 93 and the second contact holes 92, 94 of the polycrystalline silicon layer by applying CVD method and sources 95, 97 and drains 96, 98 are defined as shown in
In the disclosure, photolithography is a technology that the particular portion of film of the wafer surface is eliminated by series of manufacturing steps. After that, a micro pattern structure of film is retained on the wave surface. Through photolithography technics process, the particular portion is finally retained on the wafer. The technology is a common technics art in the area of manufacturing thin film, and the descriptions are not repeated here.
Etching technology means that materials are removed by applying chemical reaction or physical shock. The technology is a common technics art in the area of manufacturing thin film, and the descriptions are not repeated here.
Embodiments of the present disclosure are described above, and the purpose is to provide an example to illustrate the present disclosure, not be limited. For the ordinary skill in the art, you can make various changes and modifications based on the above specification. Any modification, equivalent replacement and improvement within the spirit and principles of the present disclosure are also the scope of the present disclosure.
Number | Date | Country | Kind |
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2015 1 0964883 | Dec 2015 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2016/071397 | 1/20/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2017/107274 | 6/29/2017 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
7233372 | Murade | Jun 2007 | B2 |
7554118 | Kim | Jun 2009 | B2 |
7863617 | Hioki | Jan 2011 | B2 |
8952358 | Park | Feb 2015 | B2 |
9064831 | Noh | Jun 2015 | B2 |
9305984 | Kang | Apr 2016 | B2 |
9324740 | Lee | Apr 2016 | B2 |
9337212 | Chen | May 2016 | B2 |
9356239 | Hsu | May 2016 | B2 |
9818766 | Kim | Nov 2017 | B2 |
20030180979 | Katayama | Sep 2003 | A1 |
20050116292 | Koo | Jun 2005 | A1 |
20080042131 | Morimoto | Feb 2008 | A1 |
20080073656 | Peng | Mar 2008 | A1 |
20080087889 | Chan | Apr 2008 | A1 |
20080128704 | Morimoto | Jun 2008 | A1 |
20110120755 | Lee | May 2011 | A1 |
Number | Date | Country |
---|---|---|
1638022 | Jul 2005 | CN |
101127359 | Feb 2008 | CN |
103928341 | Jul 2014 | CN |
203895510 | Oct 2014 | CN |
104465401 | Mar 2015 | CN |
104900710 | Sep 2015 | CN |
105097666 | Nov 2015 | CN |
105097667 | Nov 2015 | CN |
101075555 | Nov 2017 | CN |
2001274087 | Oct 2001 | JP |
2009147256 | Jul 2009 | JP |
20070010805 | Jan 2007 | KR |
10-0742384 | Jul 2007 | KR |
Number | Date | Country | |
---|---|---|---|
20180047830 A1 | Feb 2018 | US |