Adam Selsley

Bio: Adam Selsley is an academic researcher from Fairchild Semiconductor International, Inc.. The author has contributed to research in topics: Layer (electronics) & Trench. The author has an hindex of 5, co-authored 8 publications receiving 768 citations. Previous affiliations of Adam Selsley include Tokyo Electron & GlobalFoundries.

Power semiconductor devices and methods of manufacture

Abstract: Various embodiments for improved power devices as well as their methods of manufacture, packaging and circuitry incorporating the same for use in a wide variety of power electronic applications are disclosed. One aspect of the invention combines a number of charge balancing techniques and other techniques for reducing parasitic capacitance to arrive at different embodiments for power devices with improved voltage performance, higher switching speed, and lower on-resistance. Another aspect of the invention provides improved termination structures for low, medium and high voltage devices. Improved methods of fabrication for power devices are provided according to other aspects of the invention. Improvements to specific processing steps, such as formation of trenches, formation of dielectric layers inside trenches, formation of mesa structures and processes for reducing substrate thickness, among others, are presented. According to another aspect of the invention, charge balanced power devices incorporate temperature and current sensing elements such as diodes on the same die. Other aspects of the invention improve equivalent series resistance (ESR) for power devices, incorporate additional circuitry on the same chip as the power device and provide improvements to the packaging of charge balanced power devices.

Trenched Shield Gate Power Semiconductor Devices and Methods of Manufacture

Abstract: A semiconductor power device includes a drift region of a first conductivity type, a well region extending above the drift region and having a second conductivity type opposite the first conductivity type, an active trench extending through the well region and into the drift region. The active trench, which includes sidewalls and bottom lined with dielectric material, is substantially filled with a first conductive layer and a second conductive layer. The second conductive layer forms a gate electrode and is disposed above the first conductive layer and is separated from the first conductive layer by an inter-electrode dielectric material. The device also includes source regions having the first conductivity type formed inside the well region and adjacent the active trench and a charge control trench that extends deeper into the drift region than the active trench and is substantially filled with material to allow for vertical charge control in the drift region. The charge control trench can be lined with a layer of dielectric material and substantially filled with conductive material. The active trench can include a second shield electrode made of conductive material disposed below the first shield electrode. The first conductive layer inside the active trench can form a secondary gate electrode that is configured to be electrically biased to a desired potential. The semiconductor device can also include a Schottky structure formed between the charge control trench and a second adjacent charge control trench.

Hybrid in-situ dry cleaning of oxidized surface layers

Abstract: According to one embodiment, the method includes providing a substrate containing a metal-containing barrier layer having an oxidized surface layer, exposing the oxidized surface layer to a flow of a first process gas containing plasma-excited argon gas to activate the oxidized surface layer and applying substrate bias power during the exposing of the oxidized surface layer to the flow of the first process gas. The method further includes exposing the activated oxidized surface layer to a second process gas containing non-plasma-excited hydrogen gas, wherein the exposure to the first process gas, in addition to activating the oxidized surface layer, facilitates chemical reduction of the activated oxidized surface layer by the second process gas containing the hydrogen gas. A thickness of the metal-containing barrier layer is not substantially changed by the hybrid in-situ dry cleaning process.

Method of forming a conductive contact

Abstract: An opening is formed within insulative material to proximate a silicon comprising substrate. Titanium is deposited within the opening to form a first layer comprising titanium suicide. It is exposed to a nitrogen containing plasma effective to transform at least an outer portion thereof into a second layer comprising titanium nitride. Titanium is deposited within the opening to form an elemental titanium comprising third layer. The third layer is exposed to a nitrogen containing plasma effective to transform at least an outer portion thereof into a layer comprising titanium nitride. A metal is deposited within the opening over the transformed third layer. Any remnant of first layer, second layer, third layer, transformed third layer and metal materials is removed from over the insulative material to form an isolated conductive contact within the opening. At least the depositing to form the first layer is by chemical vapor deposition.

Methods of forming inter-poly dielectric (IPD) layers in power semiconductor devices

Abstract: A method for forming power semiconductor devices having an inter-electrode dielectric (IPD) layer inside a trench includes providing a semiconductor substrate with a trench, lining the sidewalls and bottom of the trench with a first layer of dielectric material, filling the trench with a first layer of conductive material to form a first electrode, recessing the first layer of dielectric material and the first layer of conductive material to a first depth inside the trench, forming a layer of polysilicon material on a top surface of the dielectric material and conductive material inside the trench, oxidizing the layer of polysilicon material, and forming a second electrode inside the trench atop the oxidized layer and isolated from trench sidewalls by a second dielectric layer. The oxidation step can be enhanced by either chemically or physically altering the top portion polysilicon such as by implanting impurities.

Semiconductor device, and manufacturing method thereof

Abstract: An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Power semiconductor device

Abstract: A power semiconductor device includes trenches disposed in a first base layer of a first conductivity type at intervals to partition main and dummy cells, at a position remote from a collector layer of a second conductivity type. In the main cell, a second base layer of the second conductivity type, and an emitter layer of the first conductivity type are disposed. In the dummy cell, a buffer layer of the second conductivity type is disposed. A gate electrode is disposed, through a gate insulating film, in a trench adjacent to the main cell. A buffer resistor having an infinitely large resistance value is inserted between the buffer layer and emitter electrode. The dummy cell is provided with an inhibiting structure to reduce carriers of the second conductivity type to flow to and accumulate in the buffer layer from the collector layer.

Method of Fabricating Semiconductor Device

Abstract: A method of fabricating a semiconductor device includes preparing a semiconductor wafer having a top surface and a bottom surface. The semiconductor wafer is loaded onto a wafer chuck, and the bottom surface of the loaded semiconductor wafer faces the wafer chuck. A groove is formed in the top surface of the loaded semiconductor wafer by irradiating a second laser onto the top surface, and a reforming region is formed in the loaded semiconductor wafer under the groove by irradiating a first laser through wafer chuck and bottom surface of the semiconductor wafer into a region in which the first laser is focused. The semiconductor wafer is unloaded from the wafer chuck. The bottom surface of the semiconductor wafer is ground to decrease a thickness of the semiconductor wafer. The semiconductor wafer is separated along the groove and the reforming region, thereby forming a plurality of unit chips.

Method for Fabricating Semiconductor Device

Abstract: A method for fabricating a semiconductor device, in which a lifting phenomenon can be prevented from occurring in forming an amorphous carbon film on an etched layer having tensile stress. According to the invention, since a compression stress on the etched layer or the amorphous carbon film can be reduced or a compression stress film is formed between the etched layer or the amorphous carbon film to prevent a lifting phenomenon from occurring and thus another pattern can be formed to fabricate a highly integrated semiconductor device.

Tungsten feature fill

Abstract: Described herein are methods of filling features with tungsten and related systems and apparatus. The methods include inside-out fill techniques as well as conformal deposition in features. Inside-out fill techniques can include selective deposition on etched tungsten layers in features. Conformal and non-conformal etch techniques can be used according to various implementations. The methods described herein can be used to fill vertical features, such as in tungsten vias, and horizontal features, such as vertical NAND (VNAND) word lines. Examples of applications include logic and memory contact fill, DRAM buried word line fill, vertically integrated memory gate/word line fill, and 3-D integration with through-silicon vias (TSVs).