A novel thin-film transistor with step gate-overlapped lightly doped drain and raised source/drain design

Raised Source/Drain (RSD) and Vertical Lightly Doped Drain (LDD) Poly-Si Thin-Film Transistor

“…The thicker undoped RSD thickness following a drain implantation process led to a longer vertical LDD length that was be beneficial to lower the drain electric field, and improved the device breakdown voltage. The on-state current of all of the vertical LDD structures was lower than that of the UDD and conventional devices, because of parasitic resistance [ 9 , 22 ]. The on-current of the type C device with a thick vertical LDD was almost the same as the one with a thin vertical LDD, because most of the electron current of the type C device flowed along the channel to the drain area.…”

“…To analyze the TFT drain side electric field distributions and doping profiles for all of the RSD structures, an ISE device and process simulator was carried out for the device analysis [ 19 ]. The simulated device structures and characteristics could be adequately simulated by taking into consideration the presence of the spatially uniform density of state (DOS), the conventional drift-diffusion model, and the local impact ionization model (where we used the Chynoweth model [ 4 , 20 ]) [ 9 , 10 ]. Four exponential distributions, two tail states (donor- and acceptor-like tail states) and two deep level states (donor- and acceptor-like deep state states), were sufficient to describe the DOS in the poly-Si devices [ 21 ].…”

“…Note that the emphasis of this study was on the investigation of the physical mechanisms on the RSD structure in a thin-film transistor, rather than on a precise determination of all of the model parameters for a particular batch of devices. Thus, the simulation parameters we used in [ 9 ] were thought to be sufficiently accurate. The output performance for all of the drain/source thicknesses of type B and type D devices had almost the same I DS -V DS characteristics as the convention one, because the electron current of those TFTs all flowed along the channel to a heavy doped drain area.…”

“…In order to reduce this high drain electric field, many structures have been proposed to overcome this problem. Offset [ 6 , 7 ], lightly doped drain (LDD) [ 8 ], gate overlapped lightly doped drain (GOLDD) [ 9 ], and raised source/drain (RSD) [ 10 , 11 , 12 ] are some of the proposed schemes that can effectively reduce the drain side electric field. Conventional RSD devices contain thick source/drain (S/D) regions and a thin channel, are not self-aligned in nature, and need additional masks [ 13 ].…”

Stress and Strain Analysis and Microstructure of Al/Cu Clad Composite Fabricated by Cold Extrusion

“…At present, the preparation technologies of metal composites include cold extrusion, continuous extrusion, hydrostatic extrusion, extrusion coating, electroplating, etc. [8][9][10][11]. Products produced by these processes either have poor metallurgical bonding properties between copper and aluminum (plating aluminum wire with copper method, coated welding method, the traditional extrusion method and continuous extrusion method, etc.…”