A semiconductor structure includes: a channel layer; an active layer over the channel layer, wherein the active layer is configured to form a two-dimensional electron gas (2DEG) to be formed in the channel layer along an interface between the channel layer and the active layer; a gate electrode over a top surface of the active layer; and a source/drain electrode over the top surface of the active layer; wherein the active layer includes a first layer and a second layer sequentially disposed therein from the top surface to a bottom surface of the active layer, and the first layer possesses a higher aluminum (Al) atom concentration compared to the second layer. An HEMT structure and an associated method are also disclosed.

A method for preparing a p-type semiconductor layer, an enhanced device and a method for manufacturing the same disclosed relate to the technical field of microelectronics. The method for preparing a p-type semiconductor layer includes: preparing a p-type semiconductor layer; preparing a protective layer on the p-type semiconductor layer, in which the protective layer is made of AlN or AlGaN; and annealing the p-type semiconductor layer under protection of the protective layer. In this way, the protective layer can protect the p-type semiconductor layer from volatilization and to form high-quality surface morphology in the subsequent high-temperature annealing treatment of the p-type semiconductor layer.

In one embodiment, a product includes a structure comprising a material of a Group-III-nitride having a dopant, where a concentration of the dopant in the structure has a concentration gradient characteristic of diffusion of the dopant inward from at least a portion of a surface of the structure in a direction substantially normal to the portion of the surface. The structure has less than 1% decomposition of the Group-III-nitride at the surface of the structure.

A method for manufacturing a nitride semiconductor device includes: selectively ion-implanting an element that is other than p-type impurities and n-type impurities into a first region in a first primary surface of a gallium nitride layer so as to generate crystal defects in the first region; selectively ion-implanting a p-type impurity into a second region in the gallium nitride layer, the second region being shallower than the first region in a depth direction and being within the first region in a plan view; and thermally treating said gallium nitride layer that has been ion-implanted with said element and said p-type impurity so as to thermally diffuse said p-type impurity in the second region into a third region that is within the first region and that surrounds a bottom and sides of the second region.

A method for treating a substrate includes receiving a substrate in a vacuum process chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an interior portion underlying the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further includes altering the chemical composition of the exposed surface and a fraction of the interior portion of the III-V film layer to form an altered portion of the III-V film layer using a hydrogen-based plasma treatment, removing the altered portion of the III-V film layer using a chlorine-based plasma treatment, and repeating the altering and removing of the III-V film layer until a predetermined amount of the III-V film layer is removed from the substrate.

A method for manufacturing a nitride semiconductor device includes: selectively ion-implanting an element that is other than p-type impurities and n-type impurities into a first region in a first primary surface of a gallium nitride layer so as to generate crystal defects in the first region; selectively ion-implanting a p-type impurity into a second region in the gallium nitride layer, the second region being shallower than the first region in a depth direction and being within the first region in a plan view; and thermally treating said gallium nitride layer that has been ion-implanted with said element and said p-type impurity so as to thermally diffuse said p-type impurity in the second region into a third region that is within the first region and that surrounds a bottom and sides of the second region.

A method for activating implanted dopants and repairing damage to dopant-implanted GaN to form n-type or p-type GaN. A GaN substrate is implanted with n- or p-type ions and is subjected to a high-temperature anneal to activate the implanted dopants and to produce planar n- or p-type doped areas within the GaN having an activated dopant concentration of about 10.sup.18-10.sup.22 cm.sup.3. An initial annealing at a temperature at which the GaN is stable at a predetermined process temperature for a predetermined time can be conducted before the high-temperature anneal. A thermally stable cap can be applied to the GaN substrate to suppress nitrogen evolution from the GaN surface during the high-temperature annealing step. The high-temperature annealing can be conducted under N.sub.2 pressure to increase the stability of the GaN. The annealing can be conducted using laser annealing or rapid thermal annealing (RTA).

A manufacturing method of a vertical GaN-based semiconductor device having: a GaN-based semiconductor substrate; a GaN-based semiconductor layer including a drift region having doping concentration of an n type impurity, which is lower than that of the GaN-based semiconductor substrate, and is provided on the GaN-based semiconductor substrate; and MIS structure having the GaN-based semiconductor layer, an insulating film contacting the GaN-based semiconductor layer, and a conductive portion contacting the insulating film, the method includes: implanting an n type dopant in a back surface of the GaN-based semiconductor substrate after forming of the MIS structure, and annealing the GaN-based semiconductor substrate after the implanting of the n type dopant.

A manufacturing method of an HEMT includes: forming a heterostructure; forming a first gate layer of intrinsic semiconductor material on the heterostructure; forming a second gate layer, containing dopant impurities of a P type, on the first gate layer; removing first portions of the second gate layer so that second portions, not removed, of the second gate layer form a doped gate region; and carrying out a thermal annealing of the doped gate region so as to cause a diffusion of said dopant impurities of the P type in the first gate layer and in the heterostructure, with a concentration, in the heterostructure, that decreases as the lateral distance from the doped gate region increases.

To form p-type semiconductor regions in a gallium nitride (GaN)-based semiconductor by ion implantation. A method for manufacturing a semiconductor device comprises forming first grooves, depositing, and ion-implanting. At the step of forming the first grooves, the first grooves are formed in a stacked body including a gallium nitride (GaN)-based first semiconductor layer containing an n-type impurity and a gallium nitride (GaN)-based second semiconductor layer stacked on the first semiconductor layer and containing a p-type impurity. The first grooves each have a bottom portion located in the first semiconductor layer. At the depositing step, the p-type impurity is deposited on side portions and the bottom portions of the first grooves. At the ion-implanting step, the p-type impurity is ion-implanted into the first semiconductor layer through the first grooves.