Abstract: A thin film transistor is disclosed, comprising a substrate, a polysilicon layer overlying the substrate, a gate insulating layer overlying the polysilicon layer, a gate electrode, a dielectric interlayer overlying the gate electrode and gate insulating layer, and a source/drain electrode overlying the dielectric interlayer. Specifically, the gate electrode comprises a first electrode layer overlying the gate insulating layer and a second electrode layer essentially overlying an upper surface of the first electrode layer. The first and second electrode layers each has substantially the same profile with a taper angle of less than about 90 degrees.

Abstract: A display panel comprising at least one display area and one peripheral circuit area having electronic components for driving the display components in the display area. The electronic components in the display area are fabricated substantially on a polysilicon layer converted from amorphous silicon by a solid phase crystallization process, whereas the electronic components in the peripheral circuit area are fabricated substantially on a polysilicon layer converted from amorphous silicon first by the solid phase crystallization process and then by laser annealing. As such, display area has a more uniform poly-Si layer substantially free of defects associated with laser annealing, and the peripheral circuit has a poly-Si layer with higher electron mobility.

Abstract: A display comprises a substrate, a polysilicon layer which is crystallized by a solid phase crystallization (SPC) method, a gate dielectric layer made of silicon oxy-nitride (SiON) and formed on the polysilicon layer, and a gate electrode formed on the gate dielectric layer (i.e. SiON).

Abstract: A method of forming a liquid crystal display device includes forming an amorphous silicon layer over a substrate and forming a light reflecting layer only over a first portion of the amorphous silicon layer. The amorphous silicon layer is then irradiated with a laser to convert it to a polysilicon layer. The light reflecting layer partially reflects the light away from the first portion of the amorphous silicon layer such that a first portion of the polysilicon layer has a first polysilicon grain size and a second portion of the polysilicon layer has a second polysilicon grain size, which is larger than the first polysilicon grain size. A first plurality of thin film transistors having reduced leakage current characteristics may then be formed from the first portion of the polysilicon layer.

Abstract: A crystallizing method for forming a poly-Si film is described as follows. First, forming an activated layer on a substrate, and the molecule structure of the activated layer includes carbon, hydrogen, oxygen and silicon. And then, forming an amorphous silicon film on the activated layer. Finally, performing an annealing process to crystallize the amorphous silicon film and transform it into a poly-Si film.

Abstract: A buffer layer for promoting electron mobility. The buffer layer comprises amorphous silicon layer (a-Si) and an oxide-containing layer. The a-Si has high enough density that the particles in the substrate are prevented by the a-Si buffer layer from diffusing into the active layer. As well, the buffer, having thermal conductivity, provides a good path for thermal diffusion during the amorphous active layer's recrystallization by excimer laser annealing (ELA). Thus, the uniformity of the grain size of the crystallized silicon is improved, and electron mobility of the TFT is enhanced.

Abstract: A process for cleaning a silicon surface. First, a silicon surface is cleaned with an oxidant solution. Next, the silicon surface is rinsed with HF vapor or liquid and then with the silicon surface with hydrogen water or deionized water under megasonic agitation. Finally, the silicon surface is cleaned with an oxidant solution a second time. The present inventive cleaning process can be applied in thin film transistor (TFT) fabrication and the TFT obtained has higher electron mobility.

Abstract: A buffer layer for promoting electron mobility. The buffer layer comprises amorphous silicon layer (a-Si) and an oxide-containing layer. The a-Si has high enough density that the particles in the substrate are prevented by the a-Si buffer layer from diffusing into the active layer. As well, the buffer, having thermal conductivity, provides a good path for thermal diffusion during the amorphous active layer's recrystallization by excimer laser annealing (ELA). Thus, the uniformity of the grain size of the crystallized silicon is improved, and electron mobility of the TFT is enhanced.

Abstract: A method of forming a liquid crystal display device includes forming an amorphous silicon layer over a substrate and forming a light reflecting layer only over a first portion of the amorphous silicon layer. The amorphous silicon layer is then irradiated with a laser to convert it to a polysilicon layer. The light reflecting layer partially reflects the light away from the first portion of the amorphous silicon layer such that a first portion of the polysilicon layer has a first polysilicon grain size and a second portion of the polysilicon layer has a second polysilicon grain size, which is larger than the first polysilicon grain size. A first plurality of thin film transistors having reduced leakage current characteristics may then be formed from the first portion of the polysilicon layer.

Abstract: A low temperature polysilicon thin film transistor and a method of forming the polysilicon layer inside the thin film transistor. An amorphous silicon layer is formed over a panel. The panel has a display region and a peripheral circuit region. A metallic layer is formed over a portion of the amorphous silicon layer in the peripheral circuit region. A crystallization process is performed to transform the amorphous silicon layer in the peripheral circuit region into a polysilicon layer. Thereafter, an excimer laser annealing process is performed to increase the grain size of the polysilicon layer in the peripheral circuit region and, at the same time, transform the amorphous silicon layer in the display region into a polysilicon layer. Since the average grain size of the polysilicon layer in the peripheral circuit region is larger, electron mobility is increased as demanded.

Abstract: A low temperature polysilicon thin film transistor and method of manufacturing the same is provided. The low temperature polysilicon thin film transistor comprises a channel region. Among others, one feature of the method according to the present invention is the performance of a plasma treatment to adjust the threshold voltage of the low temperature polysilicon thin film transistor. Because the threshold voltage of the low temperature polysilicon thin film transistor can be adjusted through a plasma treatment, the manufacturing process is more flexible.

Abstract: A low temperature polysilicon thin film transistor and a method of forming the polysilicon layer inside the thin film transistor. An amorphous silicon layer is formed over a panel. The panel has a display region and a peripheral circuit region. A metallic layer is formed over a portion of the amorphous silicon layer in the peripheral circuit region. A crystallization process is performed to transform the amorphous silicon layer in the peripheral circuit region into a polysilicon layer. Thereafter, an excimer laser annealing process is performed to increase the grain size of the polysilicon layer in the peripheral circuit region and, at the same time, transform the amorphous silicon layer in the display region into a polysilicon layer. Since the average grain size of the polysilicon layer in the peripheral circuit region is larger, electron mobility is increased as demanded.

Abstract: The present invention concerns a method for manufacturing a thin film transistor on a substrate. An amorphous silicon film is deposited on the substrate. A plasma treatment is used to adjust threshold voltage (Vt) of the thin film transistor instead of conventional ion implantation Vt adjustment. A crystallizationtreatment is carried out to transform the amorphous silicon film into a polysilicon layer. According toa preferred embodiment of the present invention, to create a negative shift of the threshold voltage of the thin film transistor, oxygen-containing plasma is used at a RF power lower than 500W. To create a positive shift of the threshold voltage of the thin film transistor, ammonia plasma is used.

Abstract: A buffer layer for promoting electron mobility. The buffer layer comprises amorphous silicon layer (a-Si) and an oxide-containing layer. The a-Si has high enough density that the particles in the substrate are prevented by the a-Si buffer layer from diffusing into the active layer. As well, the buffer, having thermal conductivity, provides a good path for thermal diffusion during the amorphous active layer's recrystallization by excimer laser annealing (ELA). Thus, the uniformity of the grain size of the crystallized silicon is improved, and electron mobility of the TFT is enhanced.

Abstract: A process for cleaning a silicon surface. First, a silicon surface is cleaned with an oxidant solution. Next, the silicon surface is rinsed with HF vapor or liquid and then with the silicon surface with hydrogen water or deionized water under megasonic agitation. Finally, the silicon surface is cleaned with an oxidant solution a second time. The present inventive cleaning process can be applied in thin film transistor (TFT) fabrication and the TFT obtained has higher electron mobility.

Abstract: A process for forming a polysilicon layer. First, an amorphous silicon layer is formed. Next, the amorphous silicon layer is pre-treated such that a surface of the amorphous silicon layer is oxidized to a silicon oxide layer or nitridized to a silicon nitride layer. Next, the amorphous silicon layer is crystallized to form a polysilicon layer. TFT fabricated by the present invention has smaller Vt and higher electron mobility.

Abstract: A method for fabricating a polysilicon layer includes (a) providing a substrate; (b) forming a barrier layer on the substrate; (c) forming a porous layer on the barrier layer; (d) forming an amorphous silicon layer on the porous layer; and (e) performing laser annealing process. Additionally, a stress buffer layer can form between the barrier layer and the porous layer. Due to the low thermal conductivity of the porous layer, the polysilicon layer having larger grain size is formed.