Other

Research Development Corporation of Japan

Oki Electric Industry Co., Ltd.

Oki Electric Co., Ltd.

Soubei Suzuki

Junichi Nishizawa

Hitoshi Abe

Takashige Tamamushi

A cycle of alternately or cyclically introducing external gases containing molecules of component elements of a compound semiconductor to be formed on a substrate is repeated while appropriately controlling the pressure, substrate temperature and gas introduction rate in a crystal growth vessel, so that a monocrystal which is dimensionally as precise as a single monolayer can grow on the substrate by making use of chemical reactions on the heated substrate surface. Doped molecular layer epitaxy of a compound semiconductor comprising individual steps of introducing and evacuating a first source gas, introducing and evacuating a second source gas, and introducing and evacuating an impurity gas which contains an impurity element. The doped impurity concentration varies almost linearly with the pressure during doping in a wide range.

Growth of doped semiconductor monolayers

The thickness of a thin film of an element semiconductor may be determined by counting the number of cycles of gaseous component introductions within a crystal growth vessel. Each cycle permits at most one monolayer of growth since the pressure in the vessel during gaseous component introduction is maintained under a saturation condition. The temperature to which a substrate in the vessel is heated is that for which epitaxial growth results.

Process for forming a thin film of silicon

In a semiconductor crystal growth apparatus, a growth vessel enclosing a substrate is evacuated to an ultrahigh vacuum, and gas molecules containing a component element of a semiconductor which should grow on the substrate is introduced according to a predetermined time sequence into the growth vessel from an external gas source. Infrared radiation from an infrared radiation emitting lamp associated with the growth vessel and controlled by a temperature control unit is directed toward and onto the substrate whose temperature is to be maintained at a predetermined setting. Crystal growth of one molecular layer after another can be achieved by the apparatus with dimensional accuracy of the thickness of a single molecular layer.

Use of infrared radiation and an ellipsoidal reflection mirror

A method for fabricating a photodetector device including a single pixel or an array of pixels, each of which is constituted by a single vertical type SIT (Static Induction Transistor). First and second main electrode regions are formed on respective first and second main surfaces of a silicon wafer. Control gate and shielding gate regions, as well as drain and source regions as well, are formed using a single common masking step. As a result, the formation of these regions is precisely controlled, resulting in superior photoresponse characteristics.

Method for fabricating semiconductor photodetector

A method for forming a semiconductor photodetector array having a matrix of pixels, each constituted by a single SIT (Static Induction Transistor). A field oxide layer is formed on a first main surface of a silicon wafer. Portions of a field oxide layer are then removed from predetermined regions of the first main surface. In these predetermined regions are formed a control gate region and a shielding gate region, with the shielding gate region surrounding the control gate region. Oxide layers are formed on the control gate region and shielding gate region. Portions of the field oxide layer between the control gate region and shielding region are removed to partially expose the first main surface of the silicon wafer, and a first main electrode region is formed in the exposed portion. A first conductive electrode is then deposited on the first main region, whereupon the entirety of the first main surface of the silicon wafer is covered with a first insulating layer. Portions of the first insulating layer are then removed from the control gate region, and the entirety of the first main surface of the silicon wafer is covered with a second insulating layer. A second conductive electrode is then formed on the second insulating layer upon the control gate region. Portions of the first and second insulating layers and the oxide on the shielding gate region are removed to provide a contact hole. The first main surface of the silicon wafer is then covered with a metal layer, portions of which are subsequently removed from the control gate region. Finally, an electrode for the second main electrode region is deposited on the second main surface.

Growing community of inventors

Miyagi-ken, Japan

Soubei Suzuki