Nippon Gakki Seizo Kabushiki Kaisha

Takashi Yoshida

Takeshi Matsuyama

Jun-ichi Nishizawa

Terumoto Nonaka

Tamaki Kuki

Takayuki Kodaka

Yasunori Mochida

Katsuhiko Ishida

Masao Kosugi

A semiconductor integrated logic circuit comprises a load transistor having a carrier injecting region and a carrier extracting region and an inverter transistor having a source region, drain regions, channel regions each connected between the source region and each of the drain regions, and gate regions defining the respective channel regions therebetween. The extracting region is merged into the gate regions. The channel regions have such dimensions and an impurity concentration that the channels are closed with depletion layers extending from the gate regions at zero gate voltage. The gate regions constitute a logic input and the drains constitute logic outputs. The zero gate voltage renders the channels non-conductive and the raised voltage renders the channels conductive, thus realizing an inverter circuit useful for wired logics.

Multi-drain enhancement JFET logic (SITL) with complementary MOSFET load

A static induction transistor of the type wherein carriers are injected from a source to a drain across a potential barrier induced in a current channel and wherein the height of the potential barrier can be varied in response to a gate bias voltage applied to a gate and to a drain bias voltage applied to the drain to thereby control the magnitude of a drain current of the transistor. The product of the channel resistance R.sub.c and the true transconductance G.sub.m of the transistor is maintained less than one and the product of the true transconductance and the series resistance R.sub.s of the transistor is maintained greater than or equal to one in the low drain current region in the operative state of the transistor. The series resistance R.sub.s is the sum of a resistance of the source, a resistance from the source to the current channel, and the channel resistance from the entrance of the current channel to the position of maximum value (extrema point) of the potential barrier in the current channel. This static induction transistor has the advantage that the current-voltage characteristic curve is nearly linear over a very wide range of drain current including the low drain current region. In an upside-down structure, the above-mentioned conditions can be easily attained by selecting respective impurity concentrations and thicknesses of a substrate and an epitaxial layer grown thereon.

Static induction transistor

A vertical or horizontal type junction FET including a channel-gate structure formed by a double diffusion process in which two treatments for diffusing different impurities are executed through an identical opening provided in a diffusion mask. For fabricating a vertical type junction FET, such double diffusion process is applied to stacked upper and lower semi-conductor layers having opposite conducting types thereby forming a channel region adjacent to the upper semi-conductor layer which functions as a first gate region and forming a second gate region adjacent to the channel region and remote from the first gate region. For fabricating horizontal type junction FET, the double diffusion process stated above is applied to a single semi-conductor layer to form a first gate region thereby forming a channel region adjacent to the first gate region and a second gate region adjacent to the channel region and remote from the first gate region. In either type of junction FET's the width of each channel region is precisely determined and corresponds to the difference in the diffusion depths in the two diffusion treatments. Moreover, the impurity concentration and the concentration profile of each channel region is determined independently of those of the drain or source region. Furthermore in the manufacturing process of each FET, the second gate region is self aligned so as to overlap a corresponding channel region.

Junction field effect transistor

In an integrated injection logic (IIL) type semiconductor integrated circuit, an injector transistor is formed with a field effect transistor (FET) and an inverter transistor is formed with a bipolar transistor (BPT). The drain region of the FET is merged into the base region of the BPT. The base of the BPT constitutes a logic input and the collector of the BPT constitutes a logic output. The FET may be either of the junction type or of the insulated gate type. The carrier injection efficiency can be improved to approximately unity over a wide range of the injection current.

IIL Type semiconductor integrated circuit

In a static induction transistor of the type wherein carriers are injected from a source region to a drain region across a potential barrier induced in a current channel, and wherein the height of the potential barrier can be varied in response to a gate bias voltage applied to a gate to thereby control the magnitude of a drain current of the transistor. The product of the channel resistance R.sub.c and the true transconductance (G.sub.m) of the transistor is maintained less than one and the product of the true transconductance and the series resistance R.sub.s of the transistor is maintained greater than or equal to one in the main operative state of the transistor. The series resistance R.sub.s is the sum of a resistance of the source, a resistance from the source to the current channel, and the channel resistance from the entrance of the current channel to the position of maximum value (extrema point) of the potential barrier in the current channel. This static induction transistor has the advantage that the current-voltage characteristic curve is nearly linear over a very wide range of drain current including the low drain current region.

Method of manufacturing junction field effect transistors

A horizontal junction-type field effect transistor having a saturated drain current to drain voltage characteristic and constituting an input transistor and a vertical junction-type field effect transistor having an unsaturated drain current to drain voltage characteristic and constituting an output transistor are connected in cascode fashion to compose a compound field effect transistor. This compound field effect transistor has a saturated characteristic, a high transconductance gm and a high breakdown voltage resembling those of a pentode vacuum tube. This compound field effect transistor is constructed in the form of monolithic integrated circuitry by the combined use of the dielectric isolation technique utilizing mesa groove and the pn-junction isolation technique.

Compound field effect transistor

A field effect transistor having unsaturated characteristics comprising a plurality of current channels consisting of a semiconductor material of an impurity concentration between 1 .times. 10.sup.13 to 1 .times. 10.sup.15 atoms/c.c., each current channel having a minimum diameter between 2 and 15 .mu.m so that the depletion layer growing from the gate junction nearly but not perfectly closes the current channel at zero gate bias. This junction type field effect transistor provides unsaturated and well aligned parallel characteristic curves and reduces power loss as compared to conventional unsaturated type vertical field effect transistors.

Field effect transistor having unsaturated characteristics

A junction field effect transistor of a vertical type having: a drain region having a first conductivity type; a gate region composed of branches formed on said drain region by a selective vapor deposition or liquidous phase deposition method and having a second conductivity type opposite to the first conductivity type of the drain region, at least that surface of each of the branches of the gate region which locates on the side opposite to the drain region side being covered with an insulating layer; and source regions formed between the respective branches of the gate region by conducting a further growth of said drain region. This field effect transistor has a sufficiently reduced area of P - N junction between the gate region and the respective source regions, resulting in a marked reduction in the junction capacitance. Besides, the insulated gate region with respect to the source regions give rise to a high gate-to-source breakdown voltage property.

Junction field effect transistor of vertical type

A junction field effect transistor of vertical type whose gate region is formed on the drain region so as to protrude into the source region side. This gate region is formed to have a sufficiently minute dimension by relying on either the selective etching method, the selective oxidizing method, or the selective chemical vapor deposition method, whereby the area of junction can be substantially reduced, resulting in a marked decrease in junction capacitance, and a high current capability can be obtained.

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Hamamatsu, Japan

Takashi Yoshida