摘要:
Disclosed is a field controlled thyristor in which a first semiconductor region of N.sup.+ -type, a second semiconductor region of N-type, third semiconductor regions of P-type, a fourth semiconductor region of N.sup.- -type and a fifth semiconductor region of P.sup.+ -type are formed in a semiconductor substrate having two main surfaces, the first, second and third semiconductor regions being exposed in the first main surface and the fifth semiconductor region being exposed in the second main surface; and the third semiconductor regions of P-type are spaced from each other by a predetermined spacing. The third semiconductor regions are connected with surface-exposed semiconductor regions exposed in the first main surface. The impurity concentration in the second semiconductor region decreases from the first semiconductor region toward the third semiconductor region so that a low forward voltage drop can be achieved along with a high reverse blocking voltage. Also disclosed is a method for forming the third semiconductor regions and the surface-exposed semiconductor regions through a diffusion process alone.
摘要:
Disclosed is an improved method of growing an epitaxial layer preventing auto-doping from a doped region exposed to a surface of a semiconductor substrate. A surface of a semiconductor substrate of one conductivity type is covered with a mask having a predetermined opening. Then, impurity atoms are doped into the substrate through the opening to form a region of the other conductivity type. An epitaxial layer of one conductivity type is deposited over the exposed surface of the substrate with another mask which covers the entire surface of the region and has an area larger than that of the exposed surface of the region. The latter mask prevents auto-doping from the region of the other conductivity type. The process is usable for controlling, for example, channel widths of field effect semiconductor devices uniformly and precisely.
摘要:
A switching control circuit includes a first field controlled thyristor having a gate and a cathode between which a backward bias voltage source and a second field controlled thyristor are connected in series. Conduction of the second field controlled thyristor is controlled by controlling a voltage applied across the gate and the cathode, thereby to control conduction of the first field controlled thyristor. A large load current can be positively and safely turned on and off by a relatively small control current or voltage.
摘要:
A reverse blocking type semiconductor device capable of being rapidly turned off is disclosed in which a semiconductor substrate includes four semiconductor layers in a region sandwiched between a pair of principal surfaces in such a manner that adjacent ones of these layers are different in conductivity type from each other, one outermost layer of the layers is surrounded by the layer adjacent to the one outermost layer, the one outermost layer and the layer adjacent thereto are exposed to one principal surface, a cathode electrode kept in low-resistance contact with one outermost layer, a gate electrode is kept in low-resistance contact with the layer adjacent to the one outermost layer and lies in close proximity to the one outermost layer, an anode electrode is kept in low-resistance contact with the other outermost layer at the other principal surface, and a main operating region of the other outermost layer has an impurity concentration gradient in a direction parallel to the anode electrode.
摘要:
In a static induction semiconductor device, particular a high power static induction semiconductor device, recessed portions 12 are formed in one surface of a silicon substrate 11 of one conductivity type, gate regions 13 of the other conductivity type are formed at bottoms of the recessed portions, recessed portions 14 are formed at portions surrounded by adjacent gate regions, cathode short-circuit regions 15 of the other conductivity type are formed as an island at bottoms of the recessed portions to be extended to the surface of the silicon substrate. Cathode regions 17 extending up to the surface of the silicon substrate in succession to channel regions 16 surrounded by the cathode regions 13 and cathode short-circuit regions 15, are formed. A cathode electrode substrate 21 is formed to be contacted with the cathode short-circuit regions 15 and cathode regions 17. Carriers remaining within the channel regions at a turn-off are directly swept out into the cathode electrode substrate 21 through the cathode short-circuit regions 15, and thus it is possible to provide a static induction semiconductor device, in which a large current can be cut off at a high speed without increasing an on-resistance.
摘要:
A semiconductor device that includes a recessed portion formed by isotropic-etching through an opening in an oxide layer on a surface of the semiconductor substrate, an opening formed in an oxide layer formed on the inner surface of the recessed portion by anisotropic etching, a recessed portion formed adjacent another recessed portion by isotropic etching through the opening. An overhang portion in the oxide layers at the opening is used as a mask in successive etching steps, and the isotropic and anistropic etching steps are repeated through the same mask, to eliminate errors in stacking masks and obtaining a deep notched gate structure within a short period. A cross-sectional shape of the recessed portion includes a plurality of curved recessed portions of different curvatures. A semiconductor device thus formed includes a recessed portion having a high aspect (length/width) ratio, and a depth larger than the width.
摘要:
A P.sup.+ layer is formed on the lower surface of an N.sup.- substrate, and recesses are defined in the upper surface of the N.sup.- substrate. Then, P.sup.+ gate regions and bottom gate regions are formed in side walls and bottoms of the recesses. The N.sup.- substrate and an N.sup.- substrate are ultrasonically cleaned to remove impurities therefrom, then cleaned by pure water, and dried by a spinner. Then, while lands on the upper surface of the N.sup.- substrate are being held against the surface of the N.sup.- substrate, the N.sup.- substrates are joined to each other by heating them at 800.degree. C. in a hydrogen atmosphere.
摘要:
A gate structure including semiconductor regions each having a high impurity-concentration and being formed within respective one of recessed portions provided in a surface of a first semiconductor substrate, and then a second semiconductor substrate is brought into contact with the surface of the first semiconductor substrate. The gate structure may be formed such that each of the recessed portions is completely or partially filled with the gate structure. When the gate structure includes electrically good-conductive films of a high melting point metal or the like each formed in respective one of the recessed portions, the gate resistance can be further decreased.
摘要:
A normally-off semiconductor device with gate regions formed in a high-quality base is manufactured by forming a P.sup.+ layer in a lower surface of an N.sup.- substrate, selectively forming P.sup.+ gate regions in an upper surface of the N.sup.- substrate, forming intergate P.sup.+ regions in the upper surface of the N.sup.- substrate between the P.sup.+ gate regions, forming an N.sup.+ layer in an upper surface of an N.sup.- substrate, joining the N.sup.- substrate and the N.sup.- substrate to each other by heating them at about 800.degree. C. in a hydrogen atmosphere while the upper surface of the N.sup.- substrate and a lower surface of the N.sup.- substrate are being held against each other, and forming an anode electrode and a cathode electrode.
摘要翻译:通过在N基板的下表面中形成P +层,在N基板的上表面中选择性地形成P +栅极区域,制造在高品质基底上形成有栅极区域的常关半导体器件,形成栅极 P +栅极区域之间的N衬底的上表面中的P +区域,在N衬底的上表面中形成N +层,通过将N-衬底和N衬底彼此加热,以约800 在N基板的上表面和N基板的下表面彼此保持的同时,形成阳极电极和阴极电极。
摘要:
In a surface of a silicon substrate of one conductivity type, there are formed a plurality of depressions or recesses, gate regions of opposite conductivity type are formed at bottoms of respective recesses, gate electrodes are provided on respective gate regions, and an electrically conductive block is joined to the surface of the semiconductor substrate. Between the surface of the semiconductor substrate and the electrically conductive block a contact region having a high impurity concentration and/or an electrically conductive material layer may be provided in order to improve electrical and mechanical properties of the contact between the semiconductor substrate and the electrically conductive block. The gate region can have a high impurity concentration and a distance between a channel region and the electrically conductive block can be very small.