Abstract: The scalable planar DMOS transistor structure of the present invention comprises a scalable source region surrounded by a planar gate region. The scalable source region comprises a p-base diffusion region being formed in a n? epitaxial semiconductor layer through a ring-shaped implantation window, a n+ source diffusion ring being formed in a surface portion of the p-base diffusion region through the ring-shaped implantation window, a p+ contact diffusion region being formed in a middle semiconductor surface portion through a self-aligned implantation window being surrounded by the ring-shaped implantation window, and a self-aligned source contact window being formed on the p+ contact diffusion region and the n+ source diffusion ring surrounded by a sidewall dielectric spacer. The planar gate region comprises a patterned heavily-doped polycrystalline-silicon gate layer being formed on a gate dielectric layer and capped locally with or without metal silicide layers.

Abstract: The self-aligned Schottky-barrier clamped planar DMOS transistor structure comprises a self-aligned source region being surrounded by a planar gate region. The self-aligned source region comprises a moderately-doped p-base diffusion ring being formed in a lightly-doped N? epitaxial semiconductor layer, a heavily-doped n+ source diffusion ring being formed within the moderately-doped p-base diffusion ring, and a Schottky-barrier contact with the moderately-doped p-base diffusion ring acted as a diffusion guard ring being formed in a middle semiconductor surface portion of the self-aligned source region. The planar gate region comprises a patterned heavily-doped polycrystalline-silicon gate layer being silicided with or without metal silicide layers. The self-aligned source region further comprises a lightly-doped p? diffusion region being formed beneath a middle portion of the moderately-doped p-base diffusion ring.

Abstract: A self-aligned source structure is disclosed by the present invention, in which a p-body diffusion region is formed in an n? epitaxial silicon layer on an n+ silicon substrate through a patterned window; a p+ diffusion region is formed within the p-body diffusion region through a first self-aligned implantation window surrounded by a first sidewall dielectric spacer being formed over and on a silicon nitride layer; an n+ source diffusion ring is formed in a surface portion of the p-body diffusion region and on an extended portion of the p+ diffusion region through a second self-aligned implantation window formed between the silicon nitride layer and a masking layer surrounded by the first sidewall dielectric spacer; and a self-aligned source contact window is formed on the n+ source diffusion ring surrounded by a second sidewall dielectric spacer and on the p+ diffusion region surrounded by the n+ source diffusion ring.

Abstract: A self-aligned planar DMOS transistor structure is disclosed, in which a p-body diffusion region is selectively formed in an n?/n+ epitaxial silicon substrate; a self-aligned p+ contact diffusion region is formed within the p-body diffusion region through a first self-aligned implantation window surrounded by a first sacrificial dielectric spacer; a self-aligned n+ source diffusion ring is formed in a surface portion of the p-body diffusion region through a second self-aligned implantation window formed between a protection dielectric layer and a self-aligned implantation masking layer surrounded by the sacrificial dielectric spacer; a self-aligned source contact window is formed on the self-aligned n+ source diffusion ring surrounded by a sidewall dielectric spacer and on the self-aligned p+ contact diffusion region surrounded by the self-aligned n+ source diffusion ring; and a heavily-doped polycrystalline-silicon gate layer is selectively silicided in a self-aligned manner.

Abstract: A stack-gate flash cell structure of the present invention comprises a gate region being formed between common-source/drain regions. The common-source/drain region comprises a common-source/drain diffusion region, an etched-back planarized silicon dioxide layer being formed over a portion of a tunneling dielectric layer, and a pair of extended floating-gate spacers being formed over side portions of the etched-back planarized silicon dioxide layer. The gate region comprises a major floating-gate being integrated with nearby two extended floating-gate spacers to form an integrated floating-gate. A word line together with an intergate dielectric layer being at least formed over the integrated floating-gate are simultaneously patterned and etched. A cell isolation region is formed outside of the word line and between the common-source/drain regions. The stack-gate flash cell structure is used to implement two contactless flash memory arrays.

Abstract: A dual-bit floating-gate flash cell structure comprises a gate region being formed between a common-source region and a common-drain region. The gate region comprises a pair of floating-gates being defined by a pair of second sidewall dielectric spacers and a select-gate dielectric layer being formed between the pair of floating-gates. The common-source/drain region comprises a common-source/drain diffusion region or a pair of isolated source/drain diffusion regions being divided by a shallow trench isolation formed between a pair of first sidewall dielectric spacers. A word line being formed over an intergate dielectric layer is at least formed over the pair of floating-gates and the select-gate dielectric layer. Based on common-source/drain diffusion regions and isolated source/drain diffusion regions of the dual-bit floating-gate cell structure, two different contactless flash memory arrays are formed.

Abstract: A self-aligned split-gate flash cell structure of the present invention comprises a ridge-shaped floating-gate layer being formed on a first gate dielectric layer with a first intergate dielectric layer being formed on its top portion and a second intergate dielectric layer being formed on its inner sidewall; a control/select-gate conductive layer being formed at least over a second gate dielectric layer and the first/second intergate dielectric layers; and a common-source diffusion region and a common-drain diffusion region being implanted by aligning to the control/select-gate conductive layer. The self-aligned split-gate flash cell structure is configured into two contactless array architectures: a contactless NOR-type flash memory array and a contactless parallel common-source/drain conductive bit-lines flash memory array.

Abstract: The invention discloses methods of fabricating a semiconductor device structure having low source/drain junction capacitances and low junction leakage currents. The low source/drain junction capacitances are obtained by implementing in a self-aligned manner the major portions of the heavily-doped source and drain regions of a device over the trench-isolation region using highly-conductive silicided polycrystalline- or amorphous-semiconductor and the junction leakage currents resulting from the generation/recombination current in the depletion regions of the heavily-doped source and drain junctions due to the implant-induced defects can be much reduced or eliminated. Moreover, the contacts are made on the silicided heavily-doped source and drain regions over the trench-isolation regions, the traditional contact-induced leakage current due to the shallow source/drain junction can be completely eliminated by the present invention.

Abstract: A scalable stacked-gate flash memory device and its high-density memory arrays are disclosed by this invention. There are four different spacer techniques used to fabricate a scalable stacked-gate flash memory device: the first spacer technique is used to form the buffer-oxide spacers for implanting the channel stops of shallow-trench-isolation and oxidizing the etched surface of shallow trenches without sacrificing the active width of non-volatile semiconductor memory devices; the second spacer technique is used to highly adjust the coupling ratio of the self-aligned floating gate using a shallow-trench-isolation (STI) structure so that the applied control-gate voltage for programming and erase can be reduced; the third spacer technique is used to define the gate length of a scalable stacked-gate structure; and the fourth spacer technique is used to form the sidewall spacers for self-aligned source/drain implant, self-aligned source/drain or common buried-source silicidation, and self-aligned contacts.

Abstract: A scalable split-gate flash memory cell structure of the present invention comprises a common-source region, a scalable split-gate region being formed by a sidewall dielectric spacer, and a scalable common-drain region, wherein the scalable split-gate region comprising a floating-gate region being defined by another sidewall dielectric spacer has a tip-cathode line for erasing. The cell size of the present invention is scalable and can be made to be equal to 4F2 or smaller. The scalable split-gate flash memory cell structure is used to implement two contactless flash memory arrays: a contactless NOR-type flash memory array and a contactless parallel common-source/drain conductive bit-lines flash memory array for high speed read/write/erase operations. Moreover, the contactless flash memory arrays can be fabricated with less critical masking steps as compared to the prior art.

Abstract: A scaled stack-gate non-volatile semiconductor memory device having atapered floating-gate structure is disclosed by the present invention, in which a stack-gate structure including a masking dielectric layer over a control-gate layer over an intergate dielectric layer over a tapered floating-gate layer on a thin tunneling-dielectric layer is formed on a semiconductor substrate having an active region isolated by field-oxides and is oxidized. A deeper double-diffused source region having a graded doping profile formed near a gate edge and a shallow drain diffusion region are formed as the first embodiment of the present invention. The deeper double-diffused source and drain regions having a graded doping profile formed near two gate edges are formed as the second embodiment of the present invention. The shallower double-diffused source and drain regions having a graded doping profile formed near two gate edges are formed as the third embodiment of the present invention.

Abstract: A stack-gate structure including a masking dielectric layer over a control-gate layer over an intergate dielectric layer over a floating-gate layer formed on a gate-dielectric layer is formed on a semiconductor substrate having an active region isolated by field-oxides and is oxidized to form a first dielectric layer over the sidewalls of the control-gate layer, a second dielectric layer over the sidewalls of the floating-gate layer, and a thicker oxide layer over each side portion of the active region having a gradedoxide layer formed near two gate edges. An integrated source/drain landing island having a portion formed over a source/drain diffusion region for contact and an extended portion formed over a second dielectric layer and on a graded-oxide layer is acted as a field-emission cathode/anode. The scaled stack-gate flash memory device of the present invention can be programmed and erased through two-tunneling paths or one tunneling path without involving the channel region.

Abstract: The scaled MOSFETs having a conductive barrier-metal layer sandwiched between a metal layer or a thick silicide layer on the top and a first conductive gate layer at the bottom are disclosed by the present invention, in which the first conductive gate layer is etched to form a steep-gate structure or a taper-gate structure. The metal layer is encapsulated by a second masking dielectric layer formed on the top and a first dielectric spacer formed on both sides, no interaction would occur between the metal layer and the first conductive gate layer, a highly-conductive nature of the metal layer for gate interconnection can be preserved. A thick silicide layer is formed by a two-step self-aligned silicidation process and a conductive barrier-metal layer is formed to eliminate the interaction between the thick silicide layer and the first conductive gate layer, a highly conductive nature of the thick silicide layer for gate interconnection can be obtained.

Abstract: A high-density, high-speed, low-power, scalable split-gate memory device and its fabrication are disclosed. The channel length of a control-gate device and the channel length of a floating-gate device in a split-gate flash memory device can be tailored separately to have a dimension much smaller than the minimum feature size of technology used. A sidewall erase cathode using a thin polycrystalline-silicon layer as the floating gate may be implemented. The sidewall erase cathode may be implemented on two advanced high-density isolation structures having embedded double-sides erase cathodes and high coupling ratio to form triple-sides erase cathodes, which provide high-efficiency, self-limiting erasing from the floating gate to the control gate. Moreover, self-aligned silicidation is applied to the control gate, the source/common buried source, and the drain of the device to reduce contact and interconnect resistances.

Abstract: Non-volatile semiconductor memory device for high-density and high-speed mass storage applications is described, in which a method for simultaneously fabricating field-oxide isolation and floating gate of non-volatile semiconductor memory device having high coupling ratio and embedded double-sides erase cathodes and a method for fabricating scalable split-gate non-volatile semiconductor memory device are disclosed. The field-oxide isolation is obtained by a special multilayer oxidation masking structure of the present invention, in which the field-doping encroachment and the bird's beak extension into the active regions of the minimum feature size can be eliminated and the smaller isolation area occupied together with the embedded double-sides erase cathodes are prepared for fabricating scalable split-gate non-volatile semiconductor memory device of the present invention.