539 results about "Thermal oxide" patented technology

Methods and precursors for depositing silicon nitride films by atomic layer deposition (ALD) are provided. In some embodiments the silicon precursors comprise an iodine ligand. The silicon nitride films may have a relatively uniform etch rate for both vertical and the horizontal portions when deposited onto three-dimensional structures such as FinFETS or other types of multiple gate FETs. In some embodiments, various silicon nitride films of the present disclosure have an etch rate of less than half the thermal oxide removal rate with diluted HF (0.5%).

A method and apparatus for selectively etching doped semiconductor oxides faster than undoped oxides. The method comprises applying dissociative energy to a mixture of nitrogen trifluoride and hydrogen gas remotely, flowing the activated gas toward a processing chamber to allow time for charged species to be extinguished, and applying the activated gas to the substrate. Reducing the ratio of hydrogen to nitrogen trifluoride increases etch selectivity. A similar process may be used to smooth surface defects in a silicon surface.

A method for producing a direct bonded wafer comprising: forming a thermal oxide film or a CVD oxide film on a surface of at least one of a bond wafer and a base wafer, and bonding the wafer to the other wafer via the oxide film; subsequently thinning the bond wafer to prepare a bonded wafer; and thereafter conducting a process of annealing the bonded wafer under an atmosphere including any one of an inert gas, hydrogen and a mixed gas of an inert gas and hydrogen so that the oxide film between the bond wafer and the base wafer is removed to bond the bond wafer directly to the base wafer. Thereby, there is provided a method for producing a direct bonded wafer in which generation of voids is reduced, and a direct bonded wafer with a low void count.

Concentration of metal element which promotes crystallization of silicon and which exists within a crystalline silicon film obtained by utilizing the metal element is reduced. A first heat treatment for crystallization is performed after introducing nickel to an amorphous silicon film 103. Then, laser light is irradiated to diffuse nickel element which is concentrated locally. After that, another heat treatment is performed within an oxidizing atmosphere at a temperature higher than that of the previous heat treatment. At this time, HCl or the like is added to the atmosphere. A thermal oxide film 106 is formed in this step. At this time, gettering of the nickel element into the thermal oxide film 106 takes place. Then, the thermal oxide film 106 is removed. Thereby, a crystalline silicon film 107 having low concentration of the metal element and a high crystallinity can be obtained.

Defects at the grain boundaries of a crystal silicon film, which has been crystallized from an amorphous silicon film, are passivated without using a hydrogen plasma treatment. An underlying film and a crystal silicon film which has been crystallized from an amorphous silicon film are formed on a glass substrate. A thermal oxide film is grown on the surface of the crystal silicon film by heating in an oxygen atmosphere into which NF3 gas has been added. As the thermal oxide film is grown, non-coupled Si is generated. The defects at the grain boundaries of the crystal silicon film are passivated by the additional Si. Then, the thermal oxide film is removed and the crystal silicon film is patterned into an island shape to form an active layer of a TFT. A gate insulating film, a gate electrode and the like are then formed sequentially to complete the TFT.

Concentration of metal element which promotes crystallization of silicon and which exists within a crystal silicon film obtained by utilizing the metal element is reduced. A first heat treatment for crystallization is implemented after introducing nickel element to an amorphous silicon film 103. Then, after obtaining the crystal silicon film, another heat treatment is implemented within an oxidizing atmosphere at a temperature higher than that of the previous heat treatment. At this time, HCl or the like is added to the atmosphere. A thermal oxide film 106 is formed in this step. At this time, gettering of the nickel element into the thermal oxide film 106 takes place. Next, the thermal oxide film 106 is removed. Thereby, a crystal silicon film 107 having low concentration of the metal element and a high crystalinity can be obtained.

Medical imaging devices may comprise an array of ultrasonic transducer elements. Each transducer element may comprise a substrate having a doped surface creating a highly conducting surface layer, a layer of thermal oxide on the substrate, a layer of silicon nitride on the layer of thermal oxide, a layer of silicon dioxide on the layer of silicon nitride, and a layer of conducting thin film on the layer of silicon dioxide. The layers of silicon dioxide and thermal oxide may sandwich the layer of silicon nitride, and the layer of conducting thin film may be separated from the layer of silicon nitride by the layer of silicon dioxide.

Concentration of metal element which promotes crystallization of silicon and which exists within a crystal silicon film obtained by utilizing the metal element is reduced. A first heat treatment for crystallization is implemented after introducing nickel to an amorphous silicon film 103. Then, laser light is irradiated to diffuse the nickel element concentrated locally. After that, another heat treatment is implemented within an oxidizing atmosphere at a temperature higher than that of the previous heat treatment. A thermal oxide film 106 is formed in this step. At this time, the nickel element is gettered to the thermal oxide film 106. Then, the thermal oxide film 106 is removed. Thereby, a crystal silicon film 107 having low concentration of the metal element and a high crystallinity can be obtained.

Methods of forming a semiconductor device include forming a trench mask pattern on a semiconductor substrate having active regions and device isolation regions. A thermal oxidation process is performed using the trench mask pattern as a diffusion mask to form a thermal oxide layer defining a convex upper surface of the active regions. The thermal oxide layer and the semiconductor substrate are etched using the trench mask pattern as an etch mask to form trenches defining convex upper surfaces of the active regions. The trench mask pattern is removed to expose the convex upper surfaces of the active regions. Gate patterns are formed extending over the active regions.

A varifocal optical system includes a substantially circular membrane deposited on a substrate, and a ring-shaped PZT thin film deposited on the outer portion of the circular membrane. The membrane may be a MEMS-micromachined membrane, made of thermal oxide, polysilicon, Z_rO₂ and S_iO₂. The membrane is initially in a buckled state, and may function as a mirror or a lens. Application of an electric voltage between an inner and outer electrode on the piezoelectric thin film induces a lateral strain on the PZT thin film, thereby altering the curvature of the membrane, and thus its focal length. Focal length tuning speeds as high as 1 MHz have been demonstrated. Tuning ranges of several hundred microns have been attained. The varifocal optical system can be used in many applications that require rapid focal length tuning, such as optical switching, scanning confocal microscopy, and vibration compensation in optical storage disks.

A shielded gate trench FET is formed as follows. A trench is formed in a silicon region of a first conductivity type, the trench including a shield electrode insulated from the silicon region by a shield dielectric. An inter-poly dielectric (IPD) including a layer of thermal oxide and a layer of conformal dielectric is formed along an upper surface of the shield electrode. A gate dielectric lining at least upper trench sidewalls is formed. A gate electrode is formed in the trench such that the gate electrode is insulated from the shield electrode by the IPD.

A reduction in parasitic leakages of shallow trench isolation vias is disclosed wherein the distance between the silicon nitride liner and the active silicon sidewalls is increased by depositing an insulating oxide layer prior to deposition of the silicon nitride liner. Preferably, the insulating oxide layer comprises tetraethylorthosilicate. The method comprises of etching one or more shallow trench isolations into a semiconductor wafer; depositing an insulating oxide layer into the trench; growing a thermal oxide in the trench; and depositing a silicon nitride liner in the trench. The thermal oxide may be grown prior to or after deposition of the insulating oxide layer.

The formulations of the present invention etch doped silicon oxide compounds, such as BPSG and PSG layers, at rates greater than or equal to the etch rate of undoped silicon oxide such as thermal oxide. The formulations have the general composition of a chelating agent, preferably weakly to moderately acidic (0.1-10%; preferably 0.2-2.8%); a fluoride salt, which may be ammonium fluoride or an organic derivative of either ammonium fluoride or a polyammonium fluoride (1.65-7%; preferably 2.25-7%); a glycol solvent (71-98%; preferably 90-98%); and optionally, an amine.

Disclosed herein are various methods of forming isolation structures on FinFETs and other semiconductor devices, and the resulting devices that have such isolation structures. In one example, the method includes forming a plurality of spaced-apart trenches in a semiconducting substrate, wherein the trenches define a fin for a FinFET device, forming a layer of insulating material in the trenches, wherein the layer of insulating material covers a lower portion of the fin but not an upper portion of the fin, forming a protective material on the upper portion of the fin, and performing a heating process in an oxidizing ambient to form a thermal oxide region on the covered lower portion of the fin.

A process for fabricating a semiconductor device having reduced capacitance for high frequency circuit protection is disclosed that comprises first forming an n+ buried layer in a p-type substrate by depositing n-type dopant on the top surface of the substrate and then drive in or by implanting n-type material into the substrate, and then growing an n-type epitaxial layer atop the n+ buried layer as the device layer. Trenches that surrounds the device region with depth extending from the top surface, going through the n+ buried layer and reaching down to the substrate are then formed and then an n+ layer on the sidewalls of the trenches is formed by diffusion or ion implantation. The trenches are then filled by growing a layer of thermal oxide on the sidewalls of the trenches and followed by deposition of plasma enhanced oxide, nitride, TEOS oxide CVD oxide, or polysilicon into the trenches and then planarizing the top surface by plasma etch back or polishing. Then n+ region of the device is formed by forming an oxide layer on the top surface of the device layer and then etching the oxide by photolithography, then depositing n-type dopant material and then driving in by high temperature diffusion. Finally p+ region of the device is formed by etching the oxide using photolithography, then depositing p-type dopant material by solid or gas phase deposition or ion implantation and then driving in by high temperature diffusion so that the breakdown voltage between cathode and anode of the device is set to a targeted voltage for high frequency circuit protection.

A semiconductor device having a trench isolation layer in a semiconductor substrate is provided, wherein the trench isolation layer includes a silicon nitride liner, a silicon oxide liner; and a buried layer, wherein the buried layer includes a first buried layer for filling a lower part of the trench isolation layer and a second buried layer for filling an upper part of the trench isolation layer. A semiconductor device preferably further includes a silicon oxide layer disposed between the semiconductor substrate and the silicon nitride liner. The silicon oxide layer includes a thermal oxide layer densified at a temperature over about 800.degree. C.