Patent classifications
H01L21/0455
Method for manufacturing silicon carbide semiconductor device by selectively removing silicon from silicon carbide substrate to form protective carbon layer on silicon carbide substrate for activating dopants
A method for manufacturing a SiC semiconductor device includes the steps of: forming an impurity region in a SiC layer; forming a first carbon layer on a surface of the SiC layer having the impurity region formed therein, by selectively removing silicon from the surface; forming a second carbon layer on the first carbon layer; and heating the SiC layer having the first carbon layer and the second carbon layer formed therein.
Impurity introducing method, impurity introducing apparatus, and method of manufacturing semiconductor element
A method for introducing impurity into a semiconductor substrate includes bringing a solution containing a compound of an impurity element into contact with a primary surface of a semiconductor substrate; and irradiating the primary surface of the semiconductor substrate with a laser beam through the solution to raise a temperature of the primary surface of the semiconductor substrate at a position irradiated by the laser beam so as to dope the impurity element into the semiconductor substrate. The laser beam irradiation is performed such that the raised temperature does not return to room temperature until a prescribed dose of the impurity element is caused to be doped into the semiconductor substrate.
Method for doping impurities, method for manufacturing semiconductor device
Impurity elements are doped at a high concentration exceeding a thermodynamic equilibrium concentration into a solid material having an extremely small diffusion coefficient of the impurity element. A method for doping impurities includes steps for depositing source film made of material containing impurity elements with a film thickness on a surface of a solid target object (semiconductor substrate) made from the solid material. The film thickness is determined in consideration of irradiation time per light pulse and the energy density of the light pulse. The method also includes a step for irradiating the source film by the light pulse with the irradiation time and the energy density so as to dope the impurity elements into the target object at a concentration exceeding a thermodynamic equilibrium concentration.
Method of manufacturing silicon carbide semiconductor device by forming metal-free protection film
A method of manufacturing a silicon carbide semiconductor device includes a step of preparing a silicon carbide substrate having a first main surface and a second main surface located opposite to the first main surface, a step of forming a doped region in the silicon carbide substrate by doping the first main surface with an impurity, a step of forming a first protecting film on the doped region at the first main surface, and a step of activating the impurity included in the doped region by annealing with the first protecting film having been formed, the step of forming a first protecting film including a step of disposing a material which will form the first protecting film and in which the concentration of a metal element is less than or equal to 5 g/kg on the first main surface.
METHOD OF PRODUCING DIFFERENTLY DOPED ZONES IN A SILICON SUBSTRATE, IN PARTICULAR FOR A SOLAR CELL
What is proposed is a method of producing at least two differently heavily doped subzones (3, 5) predominantly doped with a first dopant type in a silicon substrate (1), in particular for a solar cell. The method comprises: covering at least a first subzone (3) of the silicon substrate (1) in which a heavier doping with the first dopant type is to be produced with a doping layer (7) of borosilicate glass, wherein at least a second subzone (5) of the silicon substrate (1) in which a lighter doping with the first dopant type is to be produced is not covered with the doping layer (7), and wherein boron as a dopant of a second dopant type differing from the first dopant type and oppositely polarized with respect to the same is included in the layer (7), and; heating the such prepared silicon substrate (1) to temperatures above 300 C., preferably above 900 C., in a furnace in an atmosphere containing significant quantities of the first dopant type. Additionally, at least a third doped subzone (15) doped with the second dopant type may be produced by the method additionally comprising, prior to the heating, a covering of the doping layer (7), above the third doped subzone (15) to be produced, with a further layer (17) acting as a diffusion barrier for the first dopant type.
The method uses the observation that a borosilicate glass layer seems to promote an in-diffusion of phosphorus from a gas atmosphere and may substantially facilitate a manufacturing for example of solar cells, in particular back contact solar cells.
LASER IRRADIATION APPARATUS AND LASER IRRADIATION METHOD
A laser irradiation apparatus may include a plasma generator, a laser unit configured to output a pulsed laser light beam, and a controller. The plasma generator may be configured to supply an atmospheric pressure plasma containing a dopant to a predetermined region on a semiconductor material. The controller may be configured to control the plasma generator and the laser unit to perform one of first and second controls to thereby perform doping of the dopant into the semiconductor material. The first control may cause irradiation of the predetermined region with one or more pulses of the pulsed laser light beam from start to finish of supply of the atmospheric pressure plasma to the predetermined region. The second control may cause irradiation of the predetermined region with one or more pulses of the pulsed laser light beam after supply of the atmospheric pressure plasma to the predetermined region.
Thermal doping of materials
A method is disclosed for doping a semiconductor material comprising the steps of providing a semiconductor material having a first and a second surface. A dopant precursor is applied on the first surface of the semiconductor material. A thermal energy beam is directed onto the second surface of the semiconductor material to pass through the semiconductor material and impinge upon the dopant precursor to dope the semiconductor material thereby.
Method of manufacturing silicon carbide semiconductor device
A method of manufacturing a silicon carbide semiconductor device includes the following steps. A silicon carbide substrate is prepared. A first mask layer is formed in contact with a first main surface of the silicon carbide substrate. The first mask layer includes a first layer disposed in contact with the first main surface, an etching stop layer disposed in contact with the first layer and made of a material different from that for the first layer, and a second layer disposed in contact with a surface of the etching stop layer opposite to the surface in contact with the first layer. A recess is formed in the first mask layer by etching the second layer and the etching stop layer. A first impurity region is formed in the silicon carbide substrate using the first mask layer with the recess. The first mask layer does not include a metallic element.
SEMICONDUCTOR DEVICE
A semiconductor device of an embodiment includes an SiC layer having a first and a second plane, an n-type first SiC region in the SiC layer, p-type second SiC regions between the first SiC region and the first plane, n-type third SiC regions between the second SiC regions and the first plane, a gate electrode provided between two p-type second SiC regions, a gate insulating film provided between the gate electrode and the second SiC regions, a metal layer provided between two p-type second SiC regions, and having a work function of 6.5 eV or more, and a first electrode electrically connected to the metal layer, and a second electrode, the SiC layer provided between the first electrode and the second electrode, and a part of the first SiC region is disposed between the gate insulating film and the metal layer.
Opaque Thermal Layer for Silicon Carbide Substrates
A method for thermally processing an optically nonopaque substrate using radiant energy. In some embodiments, the method includes flipping the optically nonopaque substrate to expose a non-structure side, depositing an opaque thermal layer on the non-structure side of the optically nonopaque substrate where the opaque thermal layer has a uniform thickness, flipping the optically nonopaque substrate to expose the structure side, and thermally processing the optically nonopaque substrate in excess of approximately 900 degrees Celsius. In some embodiments, the opaque thermal layer is comprised of amorphous carbon, multiple layers of amorphous carbon with adjacent layers of the multiple layers having different optical properties, or alternating layers of different materials where a first layer of the alternating layers is comprised of amorphous carbon material and where a second layer of the alternating layers is comprised of amorphous silicon (Si)-based material.