摘要:
A TFT formed on an insulating substrate source, drain and channel regions, a gate insulating film formed on at least the channel region and a gate electrode formed on the gate insulating film. Between the channel region and the drain region, a region having a higher resistivity is provided in order to reduce an Ioff current. A method for forming this structure comprises the steps of anodizing the gate electrode to form a porous anodic oxide film on the side of the gate electrode; removing a portion of the gate insulating using the porous anodic oxide film as a mask so that the gate insulating film extends beyond the gate electrode but does not completely cover the source and drain regions. Thereafter, an ion doping of one conductivity element is performed. The high resistivity region is defined under the gate insulating film.
摘要:
There is provided a method by which lightly doped drain (LDD) regions can be formed easily and at good yields in source/drain regions in thin film transistors possessing gate electrodes covered with an oxide covering. A lightly doped drain (LDD) region is formed by introducing an impurity into an island-shaped silicon film in a self-aligning manner, with a gate electrode serving as a mask. First, low-concentration impurity regions are formed in the island-shaped silicon film by using rotation-tilt ion implantation to effect ion doping from an oblique direction relative to the substrate. Low-concentration impurity regions are also formed below the gate electrode at this time. After that, an impurity at a high concentration is introduced normally to the substrate, so forming high-concentration impurity regions. In the above process, a low-concentration impurity region remains below the gate electrode and constitutes a lightly doped drain region.
摘要:
A semiconductor integrated circuit comprising thin-film transistors in each of which the second wiring is prevented from breaking at steps. A silicon nitride film is formed on gate electrodes and on gate wiring extending from the gate electrodes. Substantially triangular regions are formed out of an insulator over side surfaces of the gate electrodes and of the gate wiring. The presence of these substantially triangular side walls make milder the steps at which the second wiring goes over the gate wiring. This suppresses breakage of the second wiring.
摘要:
Disclosed herein is a process for fabricating a thin-film semiconductor device which includes (1) a step of etching a silicon film by wet etching or gas etching, the former employing a liquid containing hydrazine or ethylene diamine, the latter employing chlorine fluoride, thereby forming an island-like silicon semiconductor region having inclined edges, and (2) a step of forming thereon a gate insulating film by plasma-free process such as heated CVD. The process yields the island-like silicon region and gate insulating film completely free from plasma-induced damage. This reduces the leakage current between the source and drain (which is due to plasma-induced damage) and prevents the degradation of characteristic properties.
摘要:
There is proposed a process for performing (quasi-) anisotropic etching on a silicon-based material without using plasma. The process consists of irradiating a polycrystalline or single-crystalline silicon film or substrate with a beam of accelerated hydrogen ions, silicon ions, or rare gas ions, so that the crystalline silicon is made amorphous. Then, the amorphous silicon is placed in an atmosphere of fluorinated halogen. Since the etching rate of fluorinated halogen for amorphous silicon is greater than that for polycrystalline or single-crystalline silicon, etching takes place selectively at the area which has been irradiated with a beam of accelerated hydrogen ions, silicon ions, or rare gas ions. The selective etching permits (quasi-) anisotropic etching instead of sideward isotropic etching.
摘要:
A TFT formed on an insulating substrate source, drain and channel regions, a gate insulating film formed on at least the channel region and a gate electrode formed on the gate insulating film. Between the channel region and the drain region, a region having a higher resistivity is provided in order to reduce an Ioff current. A method for forming this structure comprises the steps of anodizing the gate electrode to form a porous anodic oxide film on the side of the gate electrode; removing a portion of the gate insulating using the porous anodic oxide film as a mask so that the gate insulating film extends beyond the gate electrode but does not completely cover the source and drain regions. Thereafter, an ion doping of one conductivity element is performed. The high resistivity region is defined under the gate insulating film.
摘要:
A semiconductor integrated circuit comprising thin-film transistors in each of which the second wiring is prevented from breaking at steps. A silicon nitride film is formed on gate electrodes and on gate wiring extending from the gate electrodes. Substantially triangular regions are formed out of an insulator over side surfaces of the gate electrodes and of the gate wiring. The presence of these substantially triangular side walls make milder the steps at which the second wiring goes over the gate wiring. This suppresses breakage of the second wiring.
摘要:
A TFT formed on an insulating substrate source, drain and channel regions, a gate insulating film formed on at least the channel region and a gate electrode formed on the gate insulating film. Between the channel region and the drain region, a region having a higher resistivity is provided in order to reduce an Ioff current. A method for forming this structure comprises the steps of anodizing the gate electrode to form a porous anodic oxide film on the side of the gate electrode; removing a portion of the gate insulating using the porous anodic oxide film as a mask so that the gate insulating film extends beyond the gate electrode but does not completely cover the source and drain regions. Thereafter, an ion doping of one conductivity element is performed. The high resistivity region is defined under the gate insulating film.
摘要:
A semiconductor integrated circuit comprising thin-film transistors in each of which the second wiring is prevented from breaking at steps. A silicon nitride film is formed on gate electrodes and on gate wiring extending from the gate electrodes. Substantially triangular regions are formed out of an insulator over side surfaces of the gate electrodes and of the gate wiring. The presence of these substantially triangular side walls make milder the steps at which the second wiring goes over the gate wiring. This suppresses breakage of the second wiring.
摘要:
A TFT formed on an insulating substrate source, drain and channel regions, a gate insulating film formed on at least the channel region and a gate electrode formed on the gate insulating film. Between the channel region and the drain region, a region having a higher resistivity is provided in order to reduce an Ioff current. A method for forming this structure comprises the steps of anodizing the gate electrode to form a porous anodic oxide film on the side of the gate electrode; removing a portion of the gate insulating using the porous anodic oxide film as a mask so that the gate insulating film extends beyond the gate electrode but does not completely cover the source and drain regions. Thereafter, an ion doping of one conductivity element is performed. The high resistivity region is defined under the gate insulating film.