Hitachi, Ltd.

Akio Mimura

Takaya Suzuki

Nobutake Konishi

Genshiro Kawachi

Kenji Miyata

Yoshikazu Hosokawa

Youmei Shinagawa

Kikuo Ono

Toshio Miyazawa

Takashi Suzuki

Jun-ichi Ohwada

Takeshi Satoh

Takashi Aoyama

Hideaki Kawakami

Yutaka Misawa

Isao Ikuta

Masaichi Nagai

Shinji Okuhara

Masao Yoshimura

Seturo Yagyu

Seturoo Yagyuu

Seturo Yagiyu

Hiroshi Suga

A crystalline semiconductor having an even surface and a large crystal grain size is formed on an economical glass substrate using a laser crystallizing technology. A series of processes, including forming an insulation film on a glass substrate; forming a semiconductor film in the first layer; crystallizing the semiconductor film in the first layer by irradiating laser light stepwise from weak energy laser light to strong energy laser light; forming a semiconductor film in a second layer having a film thickness thinner than that of the semiconductor film in the first layer; performing laser crystallization of the semiconductor thin film in the second layer by irradiating laser light stepwise from weak energy laser light to strong energy laser light, are continuously performed without exposing the workpiece to the atmosphere.

Method of fabricating a semiconductor thin film

A liquid crystal display device is provided with a pixel area on a substrate having plural gate lines, plural drain lines, plural thin film transistors and plural pixel electrodes corresponding to the plural thin film transistors, and a drive circuit area disposed at a periphery of the substrate and having a drive circuit for driving the plural thin film transistors. The thin film transistor has a polycrystalline silicon semiconductor layer formed on the substrate, a gate electrode formed on the polycrystalline silicon semiconductor layer with a gate insulating film interposed therebetween, an insulating film to cover the polycrystalline silicon semiconductor layer, the gate insulating film and the gate electrode, a drain electrode formed on the insulating film and electrically connected to the polycrystalline silicon semiconductor layer, and a source electrode formed on the insulating film, spaced from the drain electrode and electrically connected to the polycrystalline silicon semiconductor layer. The unevenness of a surface of the polycrystalline silicon semiconductor layer is within 10% of a thickness of the polycrystalline silicon semiconductor layer.

Liquid crystal display device with variations of positions of peaks of depth distributions of concentration of impurities in polycrystalline being within 10% of thickness

Liquid crystal display device having improved TFTs and a fabrication method thereof

Semiconductor film, liquid-crystal display using semiconductor film, and method of manufacture thereof

A simple and convenient method of manufacturing a CMOS TFT semiconductor circuit device wherein a doping layer doped into a first conductivity type without a mask is compensated with a dopant of a second conductivity type having a high density so that the conductivity type of the doping layer of first conductivity type is inverted into the second conductivity type, and further, in order to carry out the inversion of the conductivity type by the compensation easily and reliably, the surface density of the dopant of the doping layer of first conductivity type is reduced prior to compensating with the dopant of second conductivity type.

Manufacturing method of CMOS thin film semiconductor device and CMOS

A plane display includes a plurality of pixel capacitors, each of which includes first and second electrodes and a non-linear optical material disposed therebetween. A plurality of storage capacitors are respectively provided in association with the plurality of pixel capacitors, each of which includes the first electrode of the corresponding pixel capacitor, an insulating film, and a third electrode insulated from the first electrode through the insulating film and connected to an external power supply terminal. Additionally, a provided for each storage capacitor and connected between the third electrode of the associated storage capacitor and the external power supply terminal, for preventing a potential drop causable in the course of storing electric charge in the associated storage capacitor.

Plane display

A method for fabricating an active matrix substrate is disclosed which includes the following steps: forming an island region of a first semiconductor film on a prescribed insulating substrate; forming a first insulating film and a second semiconductor film on said first insulating film; forming a second insulating film on said second semiconductor film and thereafter forming a prescribed pattern of the second insulating film; depositing prescribed metal on the pattern and thereafter forming a compound of the second semiconductor film and the metal; removing unreacted portion of the metal; and etching said second semiconductor film and said first insulating film using said compound as a mask.

Method for fabricating a thin film transistor using a silicide as an

A thin film transistor formed on an insulating sulstrate is disclosed in which metal silicide layers are formed in a thin film made of a monocrystalline, polycrystalline, or amorphous semiconductor material, to be used as source and drain regions, and further a gate electrode includes a metal silicide layer.

Thin film transistor formed on insulating substrate

Complementary thin fillm transistors (C-TFT) formed on an insulating substrate, comprising a pair of highly resistive n-type silicon islands, a pair of heavily doped n-type regions formed in one of the islands to form source and drain regions of n-channel TFT, a pair of contacts formed on the surface of the other island and establishing a high potential barrier when the underlying region is of n-type and a low potential barrier when the underlying region is inverted to be of p-type. The process for manufacturing complementary TFTs can be simplified significantly.

Thin film semiconductor device and method of manufacturing the same

This invention relates to the structure of a field effect transistor, which is suitable for liquid crystal display of an active matrix scheme and there is disclosed a new structure for the field effect transistor, in which at least one of the source region and the drain region is of multi-layered structure, in which high impurity concentration portions and low impurity concentration portions are alternately superposed on each other.

Field effect transistor

A dielectric insulator separated substrate comprises a plurality of monocrystalline semiconductor island regions in which circuit elements are to be formed and a support region for supporting the island regions while a dielectric film formed on the supporting region electrically separates the island regions from each other. The supporting region comprises crystalline semiconductor layers and at least one oxygen diffusion preventive film laminated alternately. The extreme outer polycrystalline semiconductor layer of the supporting region is polished to such a thickness as to prevent the substrate from being curved greatly by the wedge action due to the oxygen diffusion. Since the extreme outer polycrystalline semiconductor layer thus polished has a flat surface, the handling of the substrate is easy. The substrate devoid of any curveness deformation assures a highly accurate formation of the circuit elements in the island regions.

Dielectric insulator separated substrate for semiconductor integrated

In the preparation of a dielectric-isolated substrate for semiconductor integrated circuits which comprises a plurality of silicon single crystalline islands in which circuit elements are formed, a region made of an alternate laminate of silicon polycrystalline layers and silicon oxide films for supporting the plurality of silicon single crystalline islands, and a silicon oxide film interposed between the silicon single crystalline islands and the support region for isolating each of the silicon single crystalline islands from the remaining ones and the support region, the formation of three to twelve silicon polycrystalline layers in the support region can remarkably reduce the bending of the substrate resulting from the growth stress of the silicon polycrystalline layers or from the difference in thermal expansion coefficients between the single crystalline silicon and the polycrystalline silicon, and therefore produces a dielectric-isolated substrate showing little bending.

Method of preparing a dielectric-isolated substrate for semiconductor

In a monolithic semiconductor integrated circuit, when polycrystalline semiconductor is used in a portion of substrate insulatively supporting plural semiconductor single crystal regions forming circuit elements, the oxidation process of the impurity diffusion process at high temperatures and in oxygen atmosphere is started after a passivation film such as silicon oxide or silicon nitride, to prevent oxygen from diffusing or penetrating into the surface of the polycrystalline semiconductor, has been formed on the same surface. By leaving the passivation film lying on that surface during the oxidation and diffusion process warping of the substrate that may be caused due to the diffusion or penetration of oxygen into the polycrystalline semiconductor region is prevented.

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Hitachinaka, Japan

Akio Mimura