摘要:
A process for forming an insulating layer of silicon dioxide in a silicon substrate that surrounds and electrically insulates a semiconductor device is disclosed herein. The process comprises the steps of forming a recess on the outer surface of the silicon substrate that encompasses the site of the semiconductor device by photo-resist patterned reactive ion etching, and then removing silicon on the surface of the resulting recess whose crystal structure has been damaged by the reactive ion etching. Next, dopant atoms are selectively deposited on the surface of the recess so that the surface of the recess might be rendered into a porous layer of silicon when immersed in hydrogen fluoride and subjected to an electrical current. Prior to the porousification step, silicon is epitaxially grown within the walls of the recess to form the site for a semiconductor device. The substrate is then immersed in hydrogen fluoride while a current is conducted through it in order to porousify the silicon between the device island and the rest of the substrate. Finally, the substrate is thermally oxidized in order to render the porous layer of silicon into a insulating layer of silicon dioxide. The provision of such individual insulating layers around each of the devices on the substrate allows the manufacture of a high density and radiation hard semiconductor array that is not susceptible to electrical current leakage between components.
摘要:
A plurality of electronic circuits and associated signal lines are positioned at respective locations on a base wafer. A cover wafer, which fits over the base wafer, includes a corresponding like number of locations each including one or more cavities to accommodate the electronic circuit and associated signal lines. The cover wafer includes a plurality of vias for making electrical connection to the signal lines. A multi layer metallic arrangement hermetically seals the periphery of each location as well as sealing the bottom of each via. The joined base and cover wafers may then be diced to form individual die packages.
摘要:
An improved MOS photodetector having polysilicon gate material which is made more transparent to visible light by the addition of up to 50% carbon, and preferably about 10% carbon. The surfaces of the polysilicon-carbon gates are oxidized to form a silicon dioxide dielectric layer, thus eliminating the need to deposit a separate dielectric layer for isolation of adjacent gates in an overlapping gate array. The elimination of a separate dielectric layer permits all gates to be formed directly on the substrate dielectric layer, thus providing a uniform drive voltage requirement across the array.
摘要:
A method of making a semiconductor structure for use in a static induction transistor. Three layers of a SiC material are on a substrate with the top layer covered with a thick oxide. A mask having a plurality of strips is deposited on the top of the oxide to protect the area underneath it, and an etch removes the oxide, the third layer and a small amount of the second layer, leaving a plurality of pillars. An oxidation step grows an oxide skirt around the base of each pillar and consumes the edge portions of the third layer under the oxide to form a source. An ion implantation forms gate regions between the skirts. At the same time, a plurality of guard rings is formed. Removal of all oxide results in a semiconductor structure to which source, gate and drain connections may be made to form a static induction transistor. A greater separation between a source and gate is obtained by placing a spacer layer on the sidewalls of the pillars, either before or after formation of the skirt.
摘要:
A method of aligning a gate and a source of a silicon carbide static induction transistor comprising the steps of depositing an oxide layer over the transistor, forming oxide spacers from the oxide layer where the oxide spacers are adjacent the source, depositing a metal layer over the transistor and removing the oxide spacers so that the resulting gates are accurately aligned with the source.
摘要:
In one embodiment, the disclosure relates to a method for forming a semiconductor power device by depositing a first layer of TiW on a gate region and a source region, depositing a second layer of refractory metal over the first layer of TiW at the gate region, depositing a dielectric stack over the second layer of refractory metal and a portion of the first layer of TiW, depositing an etch stop layer over a portion of the dielectric stack, depositing an interconnect layer over the etch stop layer and the dielectric stack and depositing an etch mask over the interconnect layer.
摘要:
A structure for use in a static induction transistor includes a semiconductor body having first and second semiconductor layers on a substrate, with the second layer having a dopant concentration of around an order of magnitude higher than the dopant concentration of the first layer. A plurality of sources are located on the second layer. A plurality of gates are ion implanted in the second layer, an end one of the gates being connected to all of the plurality of gates and constituting a gate bus. The gate bus has an extension connecting the gate bus in the second layer of higher dopant concentration to the first layer of lower dopant concentration. The extension is ion implanted in either a series of steps or a sloping surface which is formed in the first and second layers.
摘要:
A capacitive type MEMS switch having a conductor arrangement comprised of first and second RF conductors deposited on a substrate. A bridge member having a central enlarged portion is positioned over the conductor arrangement. In one embodiment, the first RF conductor has an end defining an open area in which is positioned a pull down electrode, with the end of the first RF conductor substantially surrounding the pull down electrode. In another embodiment, two opposed RF conductors, each having ends with first and second branches, define an open area in which a pull down electrode is positioned. A dielectric layer is deposited on the conductor arrangement such that when a pull down voltage is applied to the pull down electrode, the switch impedance is significantly reduced so as to allow signal propagation between the RF conductors.
摘要:
Systems and methods for maximizing the breakdown voltage of a semiconductor device are described. In a multiple floating guard ring design, the spacing between two consecutive sets of floating guard rings may increase with their distance from the main junction while maintaining depletion region overlap, thereby alleviating crowding and optimally spreading the electric field leading to a breakdown voltage that is close to the intrinsic material limit. In another exemplary embodiment, fabrication of floating guard rings simultaneously with the formation of another semiconductor feature allows precise positioning of the first floating guard ring with respect to the edge of a main junction, as well as precise control of floating guard ring widths and spacings. In yet another exemplary embodiment, design of the vertical separation between doped regions of a semiconductor device adjusts the device's gate-to-source breakdown voltage without affecting the device's pinch-off voltage.
摘要:
A structure for use in a static induction transistor includes a semiconductor body having first and second semiconductor layers on a substrate, with the second layer having a dopant concentration of around an order of magnitude higher than the dopant concentration of the first layer. A plurality of sources are located on the second layer. A plurality of gates are ion implanted in the second layer, an end one of the gates being connected to all of the plurality of gates and constituting a gate bus. The gate bus has an extension connecting the gate bus in the second layer of higher dopant concentration to the first layer of lower dopant concentration. The extension is ion implanted in either a series of steps or a sloping surface which is formed in the first and second layers.