Renesas Electronics Corporation

Nec Corporation

Nec C Orporation

Yasuhiro Okamoto

Tatsuo Nakayama

Hironobu Miyamoto

Takashi Inoue

Yuji Ando

Kazuki Ota

Hiroshi Kawaguchi

Yoshinao Miura

Masaaki Kuzuhara

Yasuhiro Murase

Akio Wakejima

Toshiyuki Takewaki

Naotaka Kuroda

Kazuomi Endo

Katsumi Yamanoguchi

Takayuki Nagai

Nobuo Machida

Shinichi Miyake

Kensuke Kasahara

Ryohei Nega

Ichiro Masumoto

Nobuhiro Nagura

Masaaki Kanazawa

Kenichi Hisada

Hidenori Shimawaki

Kohji Matsunaga

Koji Hataya

Atsushi Tsuboi

Tohru Kawai

Takehiro Ueda

Takashi Ide

Senichirou Nagase

Takehirou Mariko

Tatsuo Nakayawa

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.

Semiconductor device

To improve an on-resistance of a semiconductor device. A plurality of collector regions are formed at a predetermined interval on a bottom surface of a drift layer made of SiC. Next, on the bottom surface of the drift layer, both of the drift layer and a collector region via a silicide layer are connected to a collector electrode.

Semiconductor device and method of manufacturing the same

In a Schottky barrier diode region, a Schottky barrier diode is formed between an n-type drift layer and a metal layer, and in a body diode region, a p-type semiconductor region, a p-type semiconductor region, and a p-type semiconductor region are formed in order from a main surface side in the drift layer, and a body diode is formed between the p-type semiconductor region and the drift layer. An impurity concentration of the p-type semiconductor region is decreased lower than the impurity concentration of the p-type semiconductor regions, thereby increasing the reflux current flowing through the Schottky barrier diode and preventing the reflux current from flowing through the body diode.

Characteristics of a semiconductor device are improved. A method of manufacturing a semiconductor device of the invention includes a step of forming a gate insulating film over a nitride semiconductor layer. The step includes steps of forming a crystalline AlOfilm on the nitride semiconductor layer, forming a SiOfilm on the AlOfilm, and forming an amorphous AlOfilm on the SiOfilm. The step further includes steps of performing heat treatment on the amorphous AlOto crystallize the amorphous AlO, thereby forming a crystalline AlOfilm, and forming a SiOfilm on the crystalline AlOfilm. In this way, since a film stack, which is formed by alternately stacking the crystalline AlOfilms and the SiOfilms from a bottom side, is used as the gate insulating film, threshold voltage can be cumulatively increased.

Method of manufacturing semiconductor device and the semiconductor device

In a manufacturing method of a semiconductor device according to the present invention, a buffer layer including a first nitride semiconductor layer, a channel layer including a second nitride semiconductor layer, and a barrier layer including a third nitride semiconductor layer are sequentially laminated, and a fourth nitride semiconductor layer is further laminated thereover. Then, a laminate of a gate insulating film and a gate electrode is formed over a first region of the fourth nitride semiconductor layer, and a silicon nitride film is formed over the fourth nitride semiconductor layer and the laminate. By bringing the fourth nitride semiconductor layers on both sides of the gate electrode into contact with the silicon nitride film in this way, the function of suppressing 2DEG can be lowered, and the 2DEG that has been eliminated after the formation of the fourth nitride semiconductor layer can be restored. The lowering in the function of suppressing 2DEG is maintained even after the silicon nitride film is removed.

Manufacturing method of semiconductor device

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.

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 and having a band gap wider than a band gap of the first nitride semiconductor layer, a trench penetrating through the second nitride semiconductor layer and reaching an inside of the first nitride semiconductor layer, a gate electrode placed in the trench over a gate insulating film, and a first electrode and a second electrode formed over the second nitride semiconductor layer on both sides of the gate electrode, respectively.

Semiconductor device and method of manufacturing semiconductor device

Characteristics of a semiconductor device are improved. A semiconductor device includes a sequential stack of a buffer layer, a channel layer, and a barrier layer, and includes a mesa part including a fourth nitride semiconductor layer formed over the stack, and a side part formed on both sides of the mesa part and including a thin film part of the fourth nitride semiconductor layer. Generation of 2DEG is suppressed below the mesa part while being unsuppressed below the side part. In this way, the side part that disables the 2DEG suppression effect is provided on an end portion of the mesa part, thereby a distance from an end portion of the side part to the gate electrode is increased, making it possible to suppress leakage caused by a current path passing through an undesired channel formed between a gate insulating film and the mesa part.

Properties of a semiconductor device are improved. A semiconductor device is configured so as to include a voltage clamp layer, a channel underlayer, a channel layer, and a barrier layer, which are formed in order above a substrate, a trench that extends up to the middle of the channel layer while penetrating through the barrier layer, a gate electrode disposed within the trench with a gate insulating film in between, a source electrode and a drain electrode formed above the barrier layer on both sides of the gate electrode, and a fourth electrode electrically coupled to the voltage clamp layer. The fourth electrode is electrically isolated from the source electrode, and a voltage applied to the fourth electrode is different from a voltage applied to the source electrode. Consequently, threshold control can be performed. For example, a threshold of a MISFET can be increased.

Semiconductor device and method of manufacturing the semiconductor device

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.

Semiconductor device with silicon nitride film over nitride semiconductor layer and between electrodes

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 (&#x3b8;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.

Semiconductor device and method for manufacturing the same

A mesa portion of a semiconductor device, which includes a channel base layer formed of a first nitride semiconductor layer, a channel layer formed of a second nitride semiconductor layer, a barrier layer formed of a third nitride semiconductor layer, a mesa-type fourth nitride semiconductor layer, a gate insulating film that covers the mesa portion, and a gate electrode formed over the gate insulating film, is used as a co-doped layer. The mesa portion is used as the co-doped layer, so that interface charges generated at an interface between the gate insulating film and the mesa portion can be cancelled by p-type impurity or n-type impurity in the co-doped layer and a threshold potential can be improved. Further, the fourth nitride semiconductor layer is n-type until the gate insulating film is formed, and the fourth nitride semiconductor layer is made neutral or p-type after the gate insulating film is formed.

Semiconductor device and manufacturing method of semiconductor device

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.

Semiconductor device and manufacturing method thereof

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.

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Tokyo, Japan

Yasuhiro Okamoto