Abstract: A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a buffer layer on a substrate; forming a first barrier layer on the buffer layer; forming a second barrier layer on the first barrier layer; forming a first hard mask on the second barrier layer; removing the first hard mask and the second barrier layer to form a recess; and forming a p-type semiconductor layer in the recess.

Abstract: A fabricating method of a high electron mobility transistor includes providing a substrate. Then, a channel layer, an active layer, a P-type group III-V compound material layer, a metal compound material layer, a hard mask material layer and a patterned photoresist are formed to cover the substrate. Later, a dry etching process is performed to etch the hard mask material layer and the metal compound material layer to form a hard mask and a metal compound layer by taking the patterned photoresist as a mask. During the dry etching process, a spacer generated by by-products is formed to surround the patterned photoresist, the hard mask and the metal compound layer. After the dry etching process, the P-type group III-V compound material layer is etched by taking the spacer and the patterned photoresist as a mask.

Abstract: A method for forming a high electron mobility transistor is disclosed. A mesa structure having a channel layer and a barrier layer is formed on a substrate. The mesa structure has two first edges extending along a first direction and two second edges extending along a second direction. A passivation layer is formed on the substrate and the mesa structure. A first opening and a plurality of second openings connected to a bottom surface of the first opening are formed and through the passivation layer, the barrier layer and a portion of the channel layer. In a top view, the first opening exposes the two first edges of the mesa structure without exposing the two second edges of the mesa structure. A metal layer is formed in the first opening and the second openings thereby forming a contact structure.

Abstract: An enhancement mode high electron mobility transistor (HEMT) includes a group III-V semiconductor body, a group III-V barrier layer and a gate structure. The group III-V barrier layer is disposed on the group III-V semiconductor body, and the gate structure is a stacked structure disposed on the group III-V barrier layer. The gate structure includes a gate dielectric and a group III-V gate layer disposed on the gate dielectric, and the thickness of the gate dielectric is between 15 nm to 25 nm.

Abstract: A method for forming a semiconductor structure includes the steps of forming a stacked structure on a substrate, forming an insulating layer on the stacked structure, forming a passivation layer on the insulating layer, performing an etching process to form an opening through the passivation layer and the insulating layer to expose a portion of the stacked structure and an extending portion of the insulating layer, and forming a contact structure filling the opening and directly contacting the stacked structure, wherein the extending portion of the insulating layer is adjacent to a surface of the stacked structure directly contacting the contact structure.

Abstract: A method for fabricating a high electron mobility transistor (HEMT) includes the steps of forming a buffer layer on a substrate, forming a barrier layer on the buffer layer, forming a p-type semiconductor layer on the barrier layer, forming a gate electrode layer on the p-type semiconductor layer, and patterning the gate electrode layer to form a gate electrode. Preferably, the gate electrode includes an inclined sidewall.

Abstract: A semiconductor device includes a substrate, a III-V compound semiconductor layer, a gate structure, a drain structure, and a field plate. The III-V compound semiconductor layer is disposed on the substrate. The gate structure, the drain structure, and the field plate are disposed above the III-V compound semiconductor layer. The field plate is located between the gate structure and the drain structure. The field plate includes a first curved sidewall located at an edge of the field plate adjacent to the drain structure. The first curved sidewall of the field plate may be used to improve electric field distribution in the semiconductor device, and electrical performance of the semiconductor device may be enhanced accordingly.

Abstract: A method for fabricating a high electron mobility transistor (HEMT) includes the steps of forming a buffer layer on a substrate, forming a barrier layer on the buffer layer, forming a p-type semiconductor layer on the barrier layer, performing an ion implantation process to form a hole injection buffer layer (HIBL) on the p-type semiconductor layer, and then forming a gate electrode on the HIBL.

Abstract: A gallium nitride device and a method for manufacturing a high electron mobility transistor are provided. The gallium nitride device includes a substrate, a channel layer disposed on the substrate, a barrier layer disposed on the channel layer, a cap layer disposed on the barrier layer, a gate disposed on the cap layer, a source, a drain, and ohmic sidewall dams. The source and the drain are formed in the cap layer and the barrier layer. Each of the source and the drain has a trench portion, and a contact below the trench portion and protruding into the channel layer. The ohmic sidewall dams are disposed on a sidewall of the trench portion of each of the source and the drain.

Abstract: A method for fabricating a high electron mobility transistor (HEMT) includes the steps of forming a buffer layer on a substrate, forming a barrier layer on the buffer layer, forming a p-type semiconductor layer on the barrier layer, forming a hole injection buffer layer (HIBL) on the p-type semiconductor layer, and forming a gate electrode on the HIBL.

Abstract: A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a buffer layer on a substrate; forming a barrier layer on the buffer layer; forming a hard mask on the barrier layer; performing an implantation process through the hard mask to form a doped region in the barrier layer and the buffer layer; removing the hard mask and the barrier layer to form a first trench; forming a gate dielectric layer on the hard mask and into the first trench; forming a gate electrode on the gate dielectric layer; and forming a source electrode and a drain electrode adjacent to two sides of the gate electrode.

Abstract: A high electron mobility transistor includes a first III-V compound layer. A second III-V compound layer is disposed on the first III-V compound layer, wherein the composition of the first III-V compound layer and the second III-V compound layer are different from each other. A source electrode and a drain electrode are disposed on the second III-V compound layer. A gate electrode is disposed on the second III-V compound layer between the source electrode and the drain electrode. An insulating layer is disposed between the drain electrode and the gate electrode and covering the second III-V compound layer. Numerous electrodes are disposed on the insulating layer and contact the insulating layer, wherein the electrodes are positioned between the gate electrode and the drain electrode and a distribution of the electrodes decreases along a direction toward the gate electrode.

Abstract: A semiconductor device provided with features of depletion mode (D-mode) and enhancement mode (E-mode) GaN devices, including a substrate with a first region and a second region defined thereon, a GaN channel layer on the substrate, a AlGaN layer on the GaN channel layer, a p-GaN layer on the AlGaN layer in the first region, a Al-based passivation layer on the AlGaN layer and p-GaN layer, and gate contact openings, wherein the gate contact opening on the first region extends through the Al-based passivation layer to the top surface of p-GaN layer, the gate contact opening on the second region extends through the Al-based passivation layer to the surface of AlGaN layer, and the surfaces of p-GaN layer and AlGaN layer are both flat surfaces without recess feature.

Abstract: A high-electron mobility transistor includes a substrate, a buffer layer over the substrate, a barrier layer over the buffer layer, and a gate structure on the barrier layer. The gate structure includes a cap layer and a gate over the cap layer. The cap layer includes a gate-leakage suppressing region on its sidewall.

Abstract: A high electron mobility transistor includes a first III-V compound layer. A second III-V compound layer is disposed on the first III-V compound layer, wherein the composition of the first III-V compound layer and the second III-V compound layer are different from each other. A source electrode and a drain electrode are disposed on the second III-V compound layer. A gate electrode is disposed on the second III-V compound layer between the source electrode and the drain electrode. An insulating layer is disposed between the drain electrode and the gate electrode and covering the second III-V compound layer. Numerous electrodes are disposed on the insulating layer and contact the insulating layer, wherein the electrodes are positioned between the gate electrode and the drain electrode and a distribution of the electrodes decreases along a direction toward the gate electrode.

Abstract: A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a first barrier layer on a substrate; forming a p-type semiconductor layer on the first barrier layer; forming a hard mask on the p-type semiconductor layer; patterning the hard mask and the p-type semiconductor layer; and forming a spacer adjacent to the hard mask and the p-type semiconductor layer.

Abstract: A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a first barrier layer on a substrate; forming a p-type semiconductor layer on the first barrier layer; forming a hard mask on the p-type semiconductor layer; patterning the hard mask and the p-type semiconductor layer; and forming a spacer adjacent to the hard mask and the p-type semiconductor layer.

Abstract: A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a buffer layer on a substrate; forming a barrier layer on the buffer layer; forming a hard mask on the barrier layer; performing an implantation process through the hard mask to form a doped region in the barrier layer and the buffer layer; removing the hard mask and the barrier layer to form a first trench; forming a gate dielectric layer on the hard mask and into the first trench; forming a gate electrode on the gate dielectric layer; and forming a source electrode and a drain electrode adjacent to two sides of the gate electrode.

Abstract: A method for fabricating high electron mobility transistor (HEMT) includes the steps of: forming a buffer layer on a substrate; forming a first barrier layer on the buffer layer; forming a second barrier layer on the first barrier layer; forming a first hard mask on the second barrier layer; removing the first hard mask and the second barrier layer to form a recess; and forming a p-type semiconductor layer in the recess.

Abstract: A semiconductor transistor structure with reduced contact resistance includes a substrate, a channel layer on the substrate, a barrier layer on the channel layer, a two-dimensional electron gas (2DEG) layer at an interface between the barrier layer and the channel layer, and a recess in a contact region. The recess penetrates through the barrier layer and extends into the channel layer. An Ohmic contact metal is disposed in the recess. The Ohmic contact metal is in direct contact with a vertical side surface of the barrier layer in the recess and in direct contact with an inclined side surface of the 2DEG layer and the channel layer in the recess.