An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

This invention clarifies the effects of parameters and enables the mass production of a super-junction semiconductor device, which has a drift layer composed of a parallel pn layer that conducts electricity in the ON state and is depleted in the OFF state. The quantity of impurities in n drift regions is within the range between 100% and 150% or between 110% and 150% of the quantity of impurities in p partition regions. The impurity density of either one of the n drift regions and the p partition regions is within the range between 92% and 108% of the impurity density of the other regions. In addition, the width of either one of the n drift regions and the p partition regions is within the range between 94% and 106% of the width of the other regions.

Semiconductor device with alternating conductivity type layer and method of manufacturing the same

A nitride semiconductor device includes: a first semiconductor layer made of first nitride semiconductor; a second semiconductor layer formed on a principal surface of the first semiconductor layer and made of second nitride semiconductor having a bandgap wider than that of the first nitride semiconductor; a control layer selectively formed on, or above, an upper portion of the second semiconductor layer and made of third nitride semiconductor having a p-type conductivity; source and drain electrodes formed on the second semiconductor layer at respective sides of the control layer; a gate electrode formed on the control layer; and a fourth semiconductor layer formed on a surface of the first semiconductor layer opposite to the principal surface, having a potential barrier in a valence band with respect to the first nitride semiconductor and made of fourth nitride semiconductor containing aluminum.

Nitride semiconductor device

In a silicon carbide semiconductor device such as a trench gate type power MOSFET, the film thickness and the impurity concentration of a thin film silicon carbide semiconductor layer formed on a trench side face to constitute an accumulation-type channel-forming region and enable the device to operate with a low gate voltage, low on-resistance and low power loss are set so that on impression of a reverse bias voltage a pn junction between a P-type epitaxial layer and an n - -type epitaxial layer undergoes avalanche breakdown before the thin film silicon carbide semiconductor layer undergoes punch-through. By this means it is possible to obtain a target high source-drain withstand voltage.

Silicon carbide semiconductor device and manufacturing method thereof

This silicon-carbide semiconductor device (101) has a silicon-carbide substrate (10), a main electrode (52), a first barrier layer (70a), and a wiring layer (60). The main electrode (52) is provided directly on top of the silicon-carbide substrate (10). The first barrier layer (70a) is provided on top of the main electrode (52) and is made from a conductive material that does not contain aluminum. The wiring layer (60) is provided on top of the first barrier layer (70a), is isolated from the main electrode (52) by the first barrier layer (70a), and is made from a material that does contain aluminum.

Silicon carbide semiconductor device

PROBLEM TO BE SOLVED: To provide a gate drive circuit of a switching element in which a soft interruption function is operated upon detecting short circuit and dielectric breakdown can be prevented even if a narrow width pulse is inputted SOLUTION: The drive circuit of a switching element comprises a drive circuit 21 performing on/off control of a switching element 23, and a soft interruption command circuit 28 which lowers the gate terminal voltage of the switching element 23 gradually upon detecting short circuit of the switching element 23 Furthermore, an on pulse holding command circuit 11 holds on state of the output from the drive circuit 21 when a gate voltage judging comparator 16 for detecting the gate terminal voltage of the switching element 23 makes a decision that the gate terminal voltage has exceeded a specified level COPYRIGHT: (C)2005,JPO&NCIPI

Drive circuit of switching element

PROBLEM TO BE SOLVED: To obtain a Schottky barrier diode with a high breakdown voltage and a large current where a leakage current in an opposite direction is reduced by forming a second conductivity type first surface layer with large depth and mutual interval and a second conductivity type second surface layer with small depth and mutual interval on the main surface of a first conductivity type SiC semiconductor substrate for forming Schottky junction SOLUTION: A Schottky barrier diode is made of an SiC semiconductor substrate consisting of a first conductivity type first semiconductor layer 3 with a low-impurity concentration and a first conductivity type second semiconductor layer 2 with a high impurity concentration, a second conductivity type first surface layer 4 that is formed on the main surface of the said first semiconductor layer and has relatively large depth and mutual interval, a second conductivity type second surface layer 4 that is formed between the said first surface layers and has relatively small depth and mutual interval, a Schottky metal 5 that is joined to the main surface of the said first semiconductor layer and is subjected to ohmic contact with the said first surface layer and the second surface layer with low resistance, and a cathode electrode 6 that is subjected to ohmic contact with the said second semiconductor layer with low resistance

Schottky barrier diode

PROBLEM TO BE SOLVED: To provide an SiC Schottky diode which has reduced leakage current, a reverse voltage stop characteristic is improved without increasing voltage drop at conducting current in the forward direction and withstand voltage and has current heavy. SOLUTION: An SiC semiconductor substrate 1, which has a pair of main surfaces and in which the two semiconductor layers of a heavily-high doped concentration 3 and a lightly-doped 2 of a first conductivity-type are stacked, Schottky metal 5 which is formed on the first surface of the substrate 1 and forms a Schottky barrier 51 with the semiconductor layer of the lightly-doped first conductivity-type and a cathode electrode 6, which is formed on the second main surface of the substrate 1 and brought into contact with the semiconductor layer of the heavily-doped first conductivity-type in terms of ohmic resistance are installed. A plurality of buried layers 7 of a second conductivity-type, which forms a p-n junction with the semiconductor layer of the lightly-doped first conductivity-type in a part close to the first main surface in the substrate 1, and the intervals are enlarged. COPYRIGHT: (C)2000,JPO

Sic schottky diode

PROBLEM TO BE SOLVED: To control the high breakdown voltage and large current of a semiconductor switching element by forming a second-conductivity semiconductor layer which is connected with a source electrode between adjacent well layers, and making the total content of impurities in the semiconductor layer smaller than those of impurities in the well layers. SOLUTION: In a parallel-plate single-crystal silicon carbide semiconductor substrate 1 having main surfaces on its top and bottom sides, a low-resistance n+-type drain layer 2 and an n--type drift layer 3 having higher resistance than the layer 2 has are laminated upon another. A plurality of high- concentration p+-type well layers 41 is provided in the drift layer 3 from one main surface of the substrate 1 and a high-concentration n+-type source layer 5 and a p--type layer 10 containing impurities at a total content which is lower than that of impurities in the p+-type well layer 41 are formed in each p+-type well layer 41. The p--type layer 10 is brought into contact with the p-type well layers 41 on both sides. Consequently, the switching of a switching element provided with a voltage clamping function under a high-breakdown voltage and large-current condition can be inhibited.

Semiconductor switching element

PROBLEM TO BE SOLVED: To provide an electrostatic induction transistor having excellent switching characteristics that a gate power required for on/off control is reduced with a super-small loss and high breakdown strength. SOLUTION: An n-type buffer with relatively high concentration is made along one edge of a drift layer (voltage holding region) arrayed in which a thin n-layer (n column layer) 31 and a p-layer (p column layer) 32 are arrayed adjacent to each other with relatively high concentration, and a p-gate layer 31 is arranged at the surface. In this case, the n-type buffer layer is interposed between the p-gate layer and the p-column layer so that the gate layer can be electrically separated from the p-column layer by the n-type buffer layer. Also, the n-type buffer layer is provided with a p-type embedded layer to be connected with low resistance to a source electrode with a source layer, so that a channel region can be arranged between the p-type embedded layer and the p-gate layer.

秀勝小野瀬

Papers

Drive circuit of switching element

Schottky barrier diode

Sic schottky diode

Semiconductor switching element

Electrostatic induction transistor

秀勝 小野瀬

Papers

Drive circuit of switching element

Schottky barrier diode

Sic schottky diode

Semiconductor switching element

Electrostatic induction transistor

秀勝小野瀬