Abstract: The characteristics of a semiconductor device are improved. A semiconductor device has a potential fixed layer containing a p type impurity, a channel layer, and a barrier layer, formed over a substrate, and a gate electrode arranged in a trench penetrating through the barrier layer, and reaching some point of the channel layer via a gate insulation film. Source and drain electrodes are formed on opposite sides of the gate electrode. The p type impurity-containing potential fixed layer has an inactivated region containing an inactivating element such as hydrogen between the gate and drain electrodes. Thus, while raising the p type impurity (acceptor) concentration of the potential fixed layer on the source electrode side, the p type impurity of the potential fixed layer is inactivated on the drain electrode side. This can improve the drain-side breakdown voltage while providing a removing effect of electric charges by the p type impurity.

Abstract: The characteristics of a semiconductor device are improved. A semiconductor device has a potential fixed layer containing a p type impurity, a channel layer, and a barrier layer, formed over a substrate, and a gate electrode arranged in a trench penetrating through the barrier layer, and reaching some point of the channel layer via a gate insulation film. Source and drain electrodes are formed on opposite sides of the gate electrode. The p type impurity-containing potential fixed layer has an inactivated region containing an inactivating element such as hydrogen between the gate and drain electrodes. Thus, while raising the p type impurity (acceptor) concentration of the potential fixed layer on the source electrode side, the p type impurity of the potential fixed layer is inactivated on the drain electrode side. This can improve the drain-side breakdown voltage while providing a removing effect of electric charges by the p type impurity.

Abstract: A property of a semiconductor device (high electron mobility transistor) is improved. A semiconductor device having a buffer layer, a channel layer, an electron supply layer, a mesa type cap layer, a source electrode, a drain electrode and a gate insulating film covering the cap layer, and a gate electrode formed on the gate insulating film, is configured as follows. The cap layer and the gate electrode are separated from each other by the gate insulating film, and side surfaces of the cap layer, the side surfaces being closer to the drain electrode and the source electrode, have tapered shapes. For example, a taper angle (?1) of the side surface of the cap layer (mesa portion) is equal to or larger than 120 degrees. By this configuration, a TDDB life can be effectively improved, and variation in an ON-resistance can be effectively suppressed.

Abstract: A semiconductor device includes a codoped layer, a channel layer, a barrier layer, and a gate electrode disposed in a trench extending through the barrier layer and reaching a middle point in the channel layer via a gate insulating film. On both sides of the gate electrode, a source electrode and a drain electrode are formed. On the source electrode side, an n-type semiconductor region is disposed to fix a potential and achieve a charge removing effect while, on the drain electrode side, a p-type semiconductor region is disposed to improve a drain breakdown voltage. By introducing hydrogen into a region of the codoped layer containing Mg as a p-type impurity in an amount larger than that of Si as an n-type impurity where the n-type semiconductor region is to be formed, it is possible to inactivate Mg and provide the n-type semiconductor region.

Abstract: The ringing of a switching waveform of a semiconductor device is restrained. For example, an interconnect (L5) is laid which functions as a source of a power transistor (Q3) and a cathode of a diode (D4), and further functioning as a drain of a power transistor (Q4) and an anode of a diode (D3). In other words, a power transistor and a diode coupled to this power transistor in series are formed in the same semiconductor chip; and further an interconnect functioning as a drain of the power transistor and an interconnect functioning as an anode of the diode are made common to each other. This structure makes it possible to decrease a parasite inductance between the power transistor and the diode coupled to each other in series.

Abstract: The characteristics of a semiconductor device are improved. A semiconductor device has a potential fixed layer containing a p type impurity, a channel layer, and a barrier layer, formed over a substrate, and a gate electrode arranged in a trench penetrating through the barrier layer, and reaching some point of the channel layer via a gate insulation film. Source and drain electrodes are formed on opposite sides of the gate electrode. The p type impurity-containing potential fixed layer has an inactivated region containing an inactivating element such as hydrogen between the gate and drain electrodes. Thus, while raising the p type impurity (acceptor) concentration of the potential fixed layer on the source electrode side, the p type impurity of the potential fixed layer is inactivated on the drain electrode side. This can improve the drain-side breakdown voltage while providing a removing effect of electric charges by the p type impurity.

Abstract: A MISFET is formed to include: a co-doped layer that is formed over a substrate and has an n-type semiconductor region and a p-type semiconductor region; and a gate electrode formed over the co-doped layer via a gate insulation film. The co-doped layer contains a larger amount of Mg, a p-type impurity, than that of Si, an n-type impurity. Accordingly, the carriers (electrons) resulting from the n-type impurities (herein, Si) in the co-doped layer are canceled by the carriers (holes) resulting from p-type impurities (herein, Mg), thereby allowing the co-doped layer to serve as the p-type semiconductor region. Mg can be inactivated by introducing hydrogen into, of the co-doped layer, a region where the n-type semiconductor region is to be formed, thereby allowing the region to serve as the n-type semiconductor region. By thus introducing hydrogen into the co-doped layer, the p-type semiconductor region and the n-type semiconductor region can be formed in the same layer.

Abstract: A semiconductor device includes a first nitride semiconductor layer formed over a substrate, a second nitride semiconductor layer formed over the first nitride semiconductor layer, a third nitride semiconductor layer formed over the second nitride semiconductor layer, a fourth nitride semiconductor layer formed over the third nitride semiconductor layer, a trench that penetrates the fourth nitride semiconductor layer and reaches as far as the third nitride semiconductor layer, a gate electrode disposed by way of a gate insulation film in the trench, a first electrode and a second electrode formed respectively over the fourth nitride semiconductor layer on both sides of the gate electrode, and a coupling portion for coupling the first electrode and the first nitride semiconductor layer.

Abstract: The characteristics of a semiconductor device are improved. A semiconductor device is formed so as to have a channel layer formed over a substrate, a barrier layer, a trench penetrating through the barrier layer in an opening region, and reaching some point of the channel layer, a gate electrode arranged in the trench via a gate insulation film, and an insulation film formed over the barrier layer outside the opening region. Then, the insulation film has a lamination structure of a Si-rich silicon nitride film, and a N-rich silicon nitride film situated thereunder. Thus, the upper layer of the insulation film is set as the Si-rich silicon nitride film. This enables the improvement of the breakdown voltage, and further, enables the improvement of the etching resistance. Whereas, the lower layer of the insulation film is set as the N-rich silicon nitride film. This can suppress collapse.

Abstract: A method of manufacturing a semiconductor device includes forming a first nitride semiconductor layer, forming thereover a second nitride semiconductor layer having a band gap wider than that of the first nitride semiconductor layer, and thereby forming a stacked body, etching the stacked body with a first film placed over the stacked body and including a first opening portion as a mask to form a trench penetrating through the second nitride semiconductor layer and reaching an inside of the first nitride semiconductor layer, causing an end portion of the first film to retreat from an end portion of the trench, forming a second film over the first film including the inside of the trench, and forming a gate electrode over the second film.

Abstract: Characteristics of a semiconductor device are improved. A semiconductor device includes a potential fixing layer, a channel underlayer, a channel layer, and a barrier layer formed above a substrate, a trench that penetrates the barrier layer and reaches as far as a middle of the channel layer, a gate electrode disposed by way of an insulation film in the trench, and a source electrode and a drain electrode formed respectively over the barrier layer on both sides of the gate electrode. A coupling portion inside the through hole that reaches as far as the potential fixing layer electrically couples the potential fixing layer and the source electrode. This can reduce fluctuation of the characteristics such as a threshold voltage and an on-resistance.

Abstract: The semiconductor device includes a trench that penetrates a barrier layer, and reaches a middle portion of a channel layer among an n+ layer, an n-type layer, a p-type layer, the channel layer, and the barrier layer which are formed above a substrate, a gate electrode arranged within the groove through a gate insulating film, and a source electrode and a drain electrode which are formed above the barrier layer on both sides of the gate electrode. The n-type layer and the drain electrode are electrically coupled by a connection portion that reaches the n+ layer. The p-type layer and the source electrode are electrically coupled by a connection portion that reaches the p-type layer. A diode including a p-type layer and an n-type layer is provided between the source electrode and the drain electrode, to thereby prevent the breaking of an element caused by an avalanche breakdown.

Abstract: The characteristics of a semiconductor device are improved. A semiconductor device has an impurity-containing potential fixed layer, and a gate electrode. A drain electrode and a source electrode are formed on the opposite sides of the gate electrode. An interlayer insulation film is formed between the gate electrode and the drain electrode, and between the gate electrode and the source electrode. The concentration of the inactivating element in the portion of the potential fixed layer under the drain electrode is higher than the concentration of the inactivating element in the portion of the potential fixed layer under the source electrode. The film thickness of the portion of the interlayer insulation film between the gate electrode and the drain electrode is different from the film thickness of the portion of the interlayer insulation film between the gate electrode and the source electrode.

Abstract: To provide a semiconductor device having improved characteristics. The semiconductor device has a substrate and thereon a buffer layer, a channel layer, a barrier layer, a trench penetrating therethrough and reaching the inside of the channel layer, a gate electrode placed in the trench via a gate insulating film, and drain and source electrodes on the barrier layer on both sides of the gate electrode. The gate insulating film has a first portion made of a first insulating film and extending from the end portion of the trench to the side of the drain electrode and a second portion made of first and second insulating films and placed on the side of the drain electrode relative to the first portion. The on resistance can be reduced by decreasing the thickness of the first portion at the end portion of the trench on the side of the drain electrode.

Abstract: A semiconductor device includes a first semiconductor layer, a second semiconductor layer formed over the first semiconductor layer, a third semiconductor layer formed over the second semiconductor layer, a gate electrode formed over the third semiconductor layer, and a gate insulating film formed between the third semiconductor layer and the gate electrode. The second semiconductor layer includes an Aly?1-yN layer (? includes Ga or In, and 0?y<1), and the third semiconductor layer includes an Alz?1-zN layer (0?z<1). y of the Aly?1-yN layer forming the second semiconductor layer increases from the third semiconductor layer to the first semiconductor layer at least in a region under the gate electrode. There is a relationship “z>y” at an interface between the second nitride semiconductor layer and the third nitride semiconductor layer.

Abstract: To improve performance of a semiconductor device. For example, on the assumption that a superlattice layer is inserted between a buffer layer and a channel layer, a concentration of acceptors introduced into nitride semiconductor layers forming a part of the superlattice layer is higher than a concentration of acceptors introduced into nitride semiconductor layers forming the other part of the superlattice layer. That is, the concentration of acceptors introduced into the nitride semiconductor layers having a small band gap is higher than the concentration of acceptors introduced into the nitride semiconductor layers having a large band gap.

Abstract: Characteristics of a semiconductor device are improved. The semiconductor device is configured to provide a trench that penetrates a barrier layer, and reaches a middle portion of a channel layer among an n+ layer, an n-type layer, a p-type layer, the channel layer, and the barrier layer which are formed above a substrate, a gate electrode arranged within the groove through a gate insulating film, and a source electrode and a drain electrode which are formed above the barrier layer on both sides of the gate electrode. The n-type layer and the drain electrode are electrically coupled to each other by a connection portion that reaches the n+ layer. The p-type layer and the source electrode are electrically coupled to each other by a connection portion that reaches the p-type layer. A diode including a p-type layer and an n-type layer is provided between the source electrode and the drain electrode, to thereby prevent the breaking of an element caused by an avalanche breakdown.

Abstract: A semiconductor device includes a first semiconductor layer, a second semiconductor layer formed over the first semiconductor layer, a gate insulating film contacting the second semiconductor layer, and a gate electrode facing the second semiconductor layer via the gate insulating film. The first semiconductor layer includes an Alx?1-xN layer (? includes Ga or In, and 0<x<1), and the second semiconductor layer includes an Aly?1-yN layer (0?y<1), in which y of the Aly?1-yN layer forming the second semiconductor layer increases at least in a region under the gate electrode as a position where y is measured approaches the first semiconductor layer.

Abstract: Characteristics of a semiconductor device are improved. A semiconductor device includes a voltage clamp layer, a channel base layer, a channel layer, and a barrier layer on a substrate. A trench extends to a certain depth of the channel layer through the barrier layer. A gate electrode is disposed on a gate insulating film within the trench. A source electrode and a drain electrode are provided on the two respective sides of the gate electrode. A coupling within a through-hole that extends to the voltage clamp layer electrically couples the voltage clamp layer to the source electrode. An impurity region containing an impurity having an acceptor level deeper than that of a p-type impurity is provided under the through-hole. The voltage clamp layer decreases variations in characteristics such as threshold voltage and on resistance. The contact resistance is reduced through hopping conduction due to the impurity in the impurity region.

Abstract: The ringing of a switching waveform of a semiconductor device is restrained. For example, an interconnect (L5) is laid which functions as a source of a power transistor (Q3) and a cathode of a diode (D4), and further functioning as a drain of a power transistor (Q4) and an anode of a diode (D3). In other words, a power transistor and a diode coupled to this power transistor in series are formed in the same semiconductor chip; and further an interconnect functioning as a drain of the power transistor and an interconnect functioning as an anode of the diode are made common to each other. This structure makes it possible to decrease a parasite inductance between the power transistor and the diode coupled to each other in series.