Abstract: A method for preparing high purity ammonia is provided, which comprises the following three steps of: (1) obtaining the required feed gases (i.e., hydrogen-nitrogen gas mixture) by catalytic cracking ammonia; (2) purifying the hydrogen-nitrogen gas mixture; and (3) synthesizing high purity ammonia by using the hydrogen- nitrogen gas mixture with high purity. In the provided method, the obtained ammonia with undesired purity is fed back to an ammonia catalytic cracking unit. The whole production system is a closed system without any discharging of ammonia and thus is environment friendly. Each step of the method can reduce cost.

Abstract: A method for preparing high purity ammonia is provided, which comprises the following three steps of: (1) obtaining the required feed gases (i.e., hydrogen-nitrogen gas mixture) by catalytic cracking ammonia; (2) purifying the hydrogen-nitrogen gas mixture; and (3) synthesizing high purity ammonia by using the hydrogen- nitrogen gas mixture with high purity. in the provided method, the obtained ammonia with undesired purity is fed back to an ammonia catalytic cracking unit. The whole production system is a closed system without any discharging of ammonia and thus is environment friendly. Each step of the method can reduce cost.

Abstract: A power device having vertical current flow through a semiconductor body of one conductivity type from a top electrode to a bottom electrode includes at least one gate electrode overlying a gate insulator on a first surface of the body, a channel region of second conductivity type in the surface of the body underlying all of the gate electrode, a first doped region of the second conductivity type contiguous with the channel region and positioned deeper in the body than the channel region and under a peripheral region of the gate electrode, and a second doped source/drain region in the surface of the body abutting the channel region and adjacent to the gate electrode. When the gate is forward biased, an inversion region extends through the channel region and electrically connects the first electrode and the second electrode with a small Vf near to the area between adjacent P bodies being flooded with electrons and denuded of holes. Therefore, at any forward bias this area conducts as an N-type region.

Abstract: A two-terminal power diode has improved reverse bias breakdown voltage and on resistance includes a semiconductor body having two opposing surfaces and a superjunction structure therebetween, the superjunction structure including a plurality of alternating P and N doped regions aligned generally perpendicular to the two surfaces. The P and N doped regions can be parallel stripes or a mesh with each region being surrounded by doped material of opposite conductivity type. A diode junction associated with one surface can be an anode region with a gate controlled channel region connecting the anode region to the superjunction structure. Alternatively, the diode junction can comprise a metal forming a Schottky junction with the one surface. The superjunction structure is within the cathode and spaced from the anode. The spacing can be varied during device fabrication.

Abstract: A power device having vertical current flow through a semiconductor body of one conductivity type from a top electrode to a bottom electrode includes at least one gate electrode overlying a gate insulator on a first surface of the body, a channel region of second conductivity type in the surface of the body underlying all of the gate electrode, a first doped region of the second conductivity type contiguous with the channel region and positioned deeper in the body than the channel region and under a peripheral region of the gate electrode, and a second doped source/drain region in the surface of the body abutting the channel region and adjacent to the gate electrode. When the gate is forward biased, an inversion region extends through the channel region and electrically connects the first electrode and the second electrode with a small Vf near to the area between adjacent P bodies being flooded with electrons and denuded of holes. Therefore, at any forward bias this area conducts as an N-type region.

Abstract: A two-terminal power diode has improved reverse bias breakdown voltage and on resistance includes a semiconductor body having two opposing surfaces and a superjunction structure therebetween, the superjunction structure including a plurality of alternating P and N doped regions aligned generally perpendicular to the two surfaces. The P and N doped regions can be parallel stripes or a mesh with each region being surrounded by doped material of opposite conductivity type. A diode junction associated with one surface can be an anode region with a gate controlled channel region connecting the anode region to the superjunction structure. Alternatively, the diode junction can comprise a metal forming a Schottky junction with the one surface. The superjunction structure is within the cathode and spaced from the anode. The spacing can be varied during device fabrication.