Abstract: A device layout is disclosed for an ESD device for protecting NMOS high voltage transistors where the SCR protection device and the two NMOS transistors are integrated. The two NMOS transistors share an n-type doped drain (ndd) area which has implanted two n+ drains, one for each of the two transistors and a p+ diffusion separates the two n+ drains. Furthermore, the ndd area has implanted an n-well which extends from halfway under the first n+ drain to halfway under the second n+ drain. In addition, the depth of the n-well exceeds the depth of the ndd area. The added p+ diffusion together with the ndd area and the p-substrate of the silicon wafer create the parasitic pnp transistors of the SCR. The shared ndd area together with the n+ sources of the NMOS transistors creates the SCR's two parasitic npn transistors.

Abstract: A device layout is disclosed for an ESD device for protecting NMOS high voltage transistors where the SCR protection device and the two NMOS transistors are integrated. The two NMOS transistors share an n-type doped drain (ndd) area which has implanted two n+ drains, one for each of the two transistors and a p+ diffusion separates the two n+ drains. Furthermore, the ndd area has implanted an n-well which extends from halfway under the first n+ drain to halfway under the second n+ drain. In addition, the depth of the n-well exceeds the depth of the ndd area. The added p+ diffusion together with the ndd area and the p-substrate of the silicon wafer create the parasitic pnp transistors of the SCR. The shared ndd area together with the n+ sources of the NMOS transistors creates the SCR's two parasitic npn transistors.

Abstract: A new design for a high voltage bipolar transistor is disclosed. Instead of a buried subcollector (which would be N+ in an NPN device), a buried P+ layer is used. The presence of this P+ layer results in pinch-off between itself and the bipolar base. This allows much higher breakdown voltages to be achieved. In particular, the device will not break down at the bottom of the base-collector junction which is the weak spot for conventional devices. A process for manufacturing this device is described. A particular feature of this new process is that the N type epitaxial layer that is grown over the P+ layer is only about half the thickness of its counterpart in the conventional device. The process is fully compatible with conventional BiCMOS processes and has lower cost.

Abstract: A device layout is disclosed for an ESD device for protecting NMOS high voltage transistors where the SCR protection device and the two NMOS transistors are integrated. The two NMOS transistors share an n-type doped drain (ndd) area which has implanted two n+ drains, one for each of the two transistors and a p+ diffusion separates the two n+ drains. Furthermore, the ndd area has implanted an n-well which extends from halfway under the first n+ drain to halfway under the second n+ drain. In addition, the depth of the n-well exceeds the depth of the ndd area. The added p+diffusion together with the ndd area and the p-substrate of the silicon wafer create the parasitic pnp transistors of the SCR. The shared ndd area together with the n+ sources of the NMOS transistors creates the SCR's two parasitic npn transistors.

Abstract: A new design for a high voltage bipolar transistor is disclosed. Instead of a buried subcollector (which would be N+ in an NPN device)d a buried P+ layer is used. The presence of this P+ layer results in pinch-off between itself and the bipolar base. This allows much higher breakdown voltages to be achieved. In particular, the device will not break down at the bottom of the base-collector junction which is the weak spot for conventional devices. A process for manufacturing this device is described. A particular feature of this new process is that the N type epitaxial layer that is grown over the P+ layer is only about half the thickness of its counterpart in the conventional device. The process is fully compatible with conventional BiCMOS processes and has lower cost.

Abstract: The device includes a N+ buried layer in a substrate. A P-well is formed in an epitaxial layer on the buried layer. N-wells surround the P-well are also formed in the epitaxial layer. One of the N-well regions acts as a drain in the structure. A plurality of field oxide regions is formed on the N-well or P-well to define the active area of the device. A gate oxide is formed on the surface of the P-well and the N-well served as the drain. A gate is formed on the gate oxide. Drain contact is formed in the N-well for drain. The source region of the device is formed in the P-well adjacent to the drain. An isolation layer is deposited on the gate. The method includes forming a N+ buried layer in a P substrate. A P epitaxial layer is then formed on the surface of the P substrate. The N-well and P-well are respectively formed in the epitaxial layer by ion implantation and thermally diffusion. A plurality of field oxide (FOX) regions are created to define the active area.

Abstract: A method for fabricating a buried layer pinched collector bipolar, (BPCB), device, sharing several process steps with simultaneously formed CMOS devices, has been developed. The BPCB device fabrication sequence features the use of polysilicon field plates,. placed on field oxide regions, in an area of an N well region in which the field oxide regions are located between subsequent P type, base and N type, collector regions. The use of the polysilicon field plates results in an increase in collector—emitter breakdown voltage, as a result of a reduction in the electric field at the surface underlying the polysilicon field plates.