Abstract: A structure of trench VDMOS transistor comprises an n? epi-layer/ n+ substrate having trench gates formed therein, which have a trench oxide layer conformally formed and filled with a first poly-Si layer. A plurality of MOS structure formed on the mesas. Doubled diffused source regions are formed asides the MOS structure. An inter-metal dielectric layer is formed on the resulted surfaces. An interconnecting metal layer patterned as two is formed on inter-metal dielectric layer. The one is for source regions and the first poly-Si layer connection by source contact plugs and the other for the gate connection by gate contact plugs. In the other embodiment, the trenches are filled with a stack layer of a first oxide layer/a first poly-Si layer. The MOS gates with their second poly-Si layer in a form of rows are formed on the first oxide layer and the mesas. An inter-metal dielectric layer is formed on the resulted surfaces.

Abstract: A structure of dual trench rectifier comprises of the following elements. A plurality of trenches are formed parallel in an n? epitaxial layer on an n+ semiconductor substrate and spaced with each other by a mesa. A plurality of recesses are formed on the mesas. Each the trench has a trench oxide layer formed on the sidewalls and bottom thereof, and a first poly silicon layer is filled therein to form MOS structures. Each the recess has a recess oxide layer formed on the sidewalls and bottom thereof, and a second poly silicon layer is filled therein to form MOS structures. A plurality of p type bodies are formed at two sides of the MOS structures in recesses. A top metal is formed above the semiconductor substrate for serving as an anode. A bottom metal is formed beneath the semiconductor substrate for serving as a cathode.

Abstract: A structure of trench MOS rectifier and a method of forming the same are disclosed including a plurality of trenches formed in the n? drift epitaxial layer, a plurality of MOS structure formed on the substrate either in discrete islands or in rows. Asides the MOS gates there are source regions formed under the mesas. A top metal served as an anode is then formed on the resulted front surface connecting the MOS gates and the adjacent source regions.

Abstract: A structure of dual trench rectifier comprises of the following elements. A plurality of trenches are formed parallel in an n? epitaxial layer on an n+ semiconductor substrate and spaced with each other by a mesa. A plurality of recesses are formed on the mesas. Each the trench has a trench oxide layer formed on the sidewalls and bottom thereof, and a first poly silicon layer is filled therein to form MOS structures. Each the recess has a recess oxide layer formed on the sidewalls and bottom thereof, and a second poly silicon layer is filled therein to form MOS structures. A plurality of p type bodies are formed at two sides of the MOS structures in recesses. A top metal is formed above the semiconductor substrate for serving as an anode. A bottom metal is formed beneath the semiconductor substrate for serving as a cathode.

Abstract: A structure of dual trench rectifier comprises of the following elements. A plurality of trenches are formed parallel in an n? epitaxial layer on an n+ semiconductor substrate and spaced with each other by a mesa. A plurality of recesses are formed on the mesas. Each the trench has a trench oxide layer formed on the sidewalls and bottom thereof, and a first poly silicon layer is filled therein to form MOS structures. Each the recess has a recess oxide layer formed on the sidewalls and bottom thereof, and a second poly silicon layer is filled therein to form MOS structures. A plurality of p type bodies are formed at two sides of the MOS structures in recesses. A top metal is formed above the semiconductor substrate for serving as an anode. A bottom metal is formed beneath the semiconductor substrate for serving as a cathode.

Abstract: A dual trench MOS transistor comprises of the following elements. A plurality of trenches are formed in an n? epitaxial layer on a heavy doped n+ semiconductor substrate and spaced to each other by one mesa. Each the trench has a trench oxide layer formed on a bottom and sidewalls thereof. A first polysilicon layer is formed in the trenches. A plurality of recesses are formed in the mesas and spaced to each other with one sub-mesa. Each the recess has a recess oxide layer formed on a bottom and sidewalls thereof. A second polysilicon layer for serving as a gate is formed in the recesses. The mesas are implanted to have implanted areas at two side of the gate. The implanted areas and the first polysilicon layer are applied to serve as the source. The rear surface of the substrate is served as the drain.

Abstract: A structure of trench MOS rectifier and a method of forming the same are disclosed including a plurality of trenches formed in the n? drift epitaxial layer, a plurality of MOS structure formed on the substrate either in discrete islands or in rows. Asides the MOS gates there are source regions formed under the mesas. A top metal served as an anode is then formed on the resulted front surface connecting the MOS gates and the adjacent source regions.

Abstract: A dual trench MOS transistor comprises of the following elements. A plurality of trenches are formed in an n? epitaxial layer on a heavy doped n+ semiconductor substrate and spaced to each other by one mesa. Each the trench has a trench oxide layer formed on a bottom and sidewalls thereof. A first polysilicon layer is formed in the trenches. A plurality of recesses are formed in the mesas and spaced to each other with one sub-mesa. Each the recess has a recess oxide layer formed on a bottom and sidewalls thereof. A second polysilicon layer for serving as a gate is formed in the recesses. The mesas are implanted to have implanted areas at two side of the gate. The implanted areas and the first polysilicon layer are applied to serve as the source. The rear surface of the substrate is served as the drain.

Abstract: A power Schottky rectifier device and method of making the same are disclosed. The Schottky rectifier device includes a LOCOS structure grown on the bottom of the trenches by using nitride spacer on the sidewall of the trenches as a thermal oxidation mask. A polycrystalline silicon layer is then filled the first trenches. Under LOCOS structure, a p doped region is optionally formed to minimize the current leakage when the device undergoes a reverse biased. A Schottky barrier silicide layer formed by sputtering and annealing steps is formed on the upper surfaces of the epi-layer and the polycrystalline silicon layer. A top metal layer served as anode is then formed on the Schottky barrier silicide layer and extended to cover a portion of field oxide region of the termination trench. A metal layer served as a cathode electrode is then formed on the backside surface of the substrate opposite to the top metal layer.

Abstract: A method of forming silicon carbide Schottky diode is disclosed. The processes required two photo-masks only. The processes are as follows: firstly, an n+-silicon carbide substrate having an n? silicon carbide drift layer is provided. Then a silicon layer is formed on the drift layer. An ion implant is carried out to dope the silicon layer. Afterward the doped silicon layer is patterned to define an active region. A thermal oxidation is then followed to form a thick oxide layer by oxidizing the silicon layer and form guard rings by using the doped silicon layer as a diffused source. The thin oxide layer on the drift layer is then removed by dilute HF dip or by BOE (buffer oxide etching) solution dip. Thereafter, a top metal layer is deposited and patterned to define as anode. After a backside layer removal, a metal layer served as cathode is formed.

Abstract: A power Schottky rectifier device having a plurality of first trenches filled in with an un-doped polycrystalline silicon layer and each first trenches also has a p-region beneath the bottom of said first trenches to block out reverse current while a reverse biased is applied and to reduce minority carrier while forward biased is applied. Thus, the power Schottky rectifier device can provide first fast switch speed. The power Schottky rectifier device is formed with termination region at an outer portion of the substrate. The manufacture method is also provided.

Abstract: A power Schottky rectifier device having pluralities of trenches are disclosed. The Schottky barrier rectifier device includes field oxide region having p-doped region formed thereunder to avoid premature of breakdown voltage and having a plurality of trenches formed in between field oxide regions to increase the anode area thereto increase forward current capacity or to shrinkage the planar area for driving the same current capacity. Furthermore, the trenches have rounded corners to alleviate current leakage and LOCOS region in the active region to relief stress during the bonding process. The processes for power Schottky barrier rectifier device including termination region formation need only three masks and thus can gain the benefits of cost down.

Abstract: A power Schottky rectifier device and its fabrication method are disclosed. The method comprises the following steps: First, a semiconductor substrate having a relatively heavily doped n+ doped layer and a lightly doped is provided. A buried p region is then formed in the epi layer by ion implantation. Afterward, a first oxide layer and a nitride layer are then successively formed on the epi layer. The result structure is then patterned to form trenches. Subsequently, a thermal oxidation step is performed to recover etch damage. A wet etch is then performed to remove the thin oxide layer in the trench to expose the silicon in the sidewall. After that, a silicidation process is then performed to form silicide layer on the n-epi-layer in the trenches. After a removal of un-reacted metal layer, a top metal layer is then formed on the silicide layer and on the first oxide layer or nitride layer. The top metal layer on the termination region portion is then patterned to define anode.

Abstract: A power Schottky rectifier device and method of making the same are disclosed. The Schottky rectifier device including a LOCOS structure and two p-type doping regions, which are positioned one above another therein to isolate cells so as to avoid premature of breakdown voltage. The Schottky rectifier device comprises: an n? drift layer formed on an n+ substrate; a cathode metal layer formed on a surface of the n+ substrate opposite the n? drift layer; a pair of field oxide regions and termination region formed into the n? drift layer and each spaced from each other by the mesas, where the mesas have metal silicide layer formed thereon. A top metal layer formed on the field oxide regions and termination region and contact with the silicide layer.

Abstract: A Schottky diode structure and a method of making the same are disclosed. The method comprises following steps: firstly, a semiconductor substrate having a first conductive layer and an epi-layer doped with the same type impurities is provided. Then a first oxide layer is form on the epi layer. A patterning step to pattern first oxide layer and recess the epi layer (optional) is then followed to define guard rings. After stripping the photoresist pattern, a polycrystalline silicon layer formation is then followed. A boron and/or BF2+ ion implant is then performed. Subsequently, a high temperature drive in process and oxidation process to oxidize the polycrystalline silicon layer and drive ions is then carried out. A second mask and etch steps are then performed to open the active regions. A metallization process is then done. A third mask and etch steps are then implemented to define anode. Finally, a backside metal layer is then formed and serves as a cathode.

Abstract: A power Schottky rectifier device and method of making the same are disclosed. The Schottky rectifier device including a LOCOS structure and two p-type doping regions, which are positioned one above another therein to isolate cells so as to avoid premature of breakdown voltage. The Schottky rectifier device comprises: an n− drift layer formed on an n+ substrate; a cathode metal layer formed on a surface of the n+ substrate opposite the n-drift layer; a pair of field oxide regions and termination region formed into the n− drift layer and each spaced from each other by the mesas, where the mesas have metal silicide layer formed thereon. A top metal layer formed on the field oxide regions and termination region and contact with the silicide layer.