Abstract:
In order to improve the characteristics of a semiconductor device including: a channel layer and a barrier layer formed above a substrate; and a gate electrode arranged over the barrier layer via a gate insulating film, the semiconductor device is configured as follows. A silicon nitride film is provided over the barrier layer between a source electrode and the gate electrode, and is also provided over the barrier layer between a drain electrode and the gate electrode GE. The surface potential of the barrier layer is reduced by the silicon nitride film, thereby allowing two-dimensional electron gas to be formed. Thus, by selectively forming two-dimensional electron gas only in a region where the silicon nitride film is formed, a normally-off operation can be performed even if a trench gate structure is not adopted.
Abstract:
To improve characteristics of a semiconductor device. A first p-type semiconductor region having an impurity of a conductivity type opposite from that of a drift layer is arranged in the drift layer below a trench, and a second p-type semiconductor region is further arranged that is spaced at a distance from a region where the trench is formed as seen from above and that has the impurity of the conductivity type opposite from that of the drift layer. The second p-type semiconductor region is configured by a plurality of regions arranged at a space in a Y direction (depth direction in the drawings). Thus, it is possible to reduce the specific on-resistance while maintaining the breakdown voltage of the gate insulating film by providing the first and second p-type semiconductor regions and further by arranging the second p-type semiconductor region spaced by the space.
Abstract:
Semiconductor device has a cell region and a peripheral region, and has a drift layer, a trench, an gate dielectric film on an inner wall of the trench, a gate electrode, and a p-type first semiconductor region below the trench in the cell region on a semiconductor substrate. Further, in the peripheral region on the semiconductor substrate, p-type second semiconductor region is formed in the same layer as the p-type first semiconductor region. a width of the p-type first semiconductor region and a width of the p-type second semiconductor region are different.
Abstract:
Characteristics of a semiconductor device using a nitride semiconductor are improved. A semiconductor device of the present invention includes a buffer layer, a channel layer, a barrier layer, a mesa-type 2DEG dissolving layer, a source electrode, a drain electrode, a gate insulating film formed on the mesa-type 2DEG dissolving layer, and an overlying gate electrode. The gate insulating film of the semiconductor device includes a sputtered film formed on the mesa-type 2DEG dissolving layer and a CVD film formed on the sputtered film. The sputtered film is formed in a non-oxidizing atmosphere by a sputtering process using a target including an insulator. This makes it possible to reduce positive charge amount at a MOS interface and in gate insulating film and increase a threshold voltage, and thus improve normally-off characteristics.
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 Alyα1-yN layer (α includes Ga or In, and 0≦y y” at an interface between the second nitride semiconductor layer and the third 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:
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 reliability of a field effect transistor made of a nitride semiconductor material is improved. An ohmic electrode includes a plurality of unit electrodes isolated to be separated from each other. With this configuration, an on-state current can be prevented from flowing in the unit electrodes in a y-axial direction (negative direction). Further, in the respective unit electrodes, a current density of the on-state current flowing in the y-axial direction (negative direction) can be prevented from increasing. As a result, an electromigration resistance of the ohmic electrode can be improved.
Abstract:
Semiconductor device has a cell region and a peripheral region, and has a drift layer, a trench, an gate dielectric film on an inner wall of the trench, a gate electrode, and a p-type first semiconductor region below the trench in the cell region on a semiconductor substrate. Further, in the peripheral region on the semiconductor substrate, p-type second semiconductor region is formed in the same layer as the p-type first semiconductor region. a width of the p-type first semiconductor region and a width of the p-type second semiconductor region are different.
Abstract:
In a semiconductor device in a wafer state, an element region and a scribe region are defined in one main surface of a semiconductor substrate. In the element region, a vertical MOS transistor is formed as a semiconductor element. In the scribe region, an n-type column region and a p-type column region are defined. An n-type column resistor is formed in the n-type column region. A p-type column resistor is formed in the p-type column region.