Abstract:
A method [300] is disclosed for the definition of the poly-1 layer [220] in a semiconductor wafer. A non-critical mask [227] is used to recess field oxides in the periphery [216] prior to poly-1 deposition [309] by an amount equal to the final poly-1 thickness [226]. A complimentary non-critical mask [222] is used to permit CMP [223] of the core [215] to expose the tops of core oxide mesas [225] from the shallow isolation trenches [210].
Abstract:
Processes for doping and saliciding word lines (20) in a virtual ground array flash memory device without causing shorting between bit lines (26) are disclosed. According to one aspect, word lines (20) are doped prior to patterning the poly layer from which the word lines (20) are formed in the core region. Thereby, the poly layer protects the substrate between the word lines (20) from doping that could cause shorting between bit lines (26). According to another aspect, word lines (20) are exposed while spacer material, dielectric, or like material protects the substrate between word lines (20). The spacer material or dielectric prevents the substrate from becoming salicided in a manner that, like doping, could cause shorting between bit lines (26). Disclosed are virtual ground array flash memory devices with doped and salicided word lines (20), but no shorting between bit lines (26) even in virtual ground arrays where there are no oxide island isolation regions (28) between bit lines (26).
Abstract:
A method for performing a bit line implant is disclosed. The method includes forming a group of structures (1410) on an oxide-nitride-oxide stack (1220, 1230, 1240) of a semiconductor device (1200). Each structure of the group of structures includes a polysilicon portion (1250) and a hard mask portion (1260). A first structure (1410) of the group of structures is separated from a second structure (1410) of the group of structures by less than 100 nanometers. The method further includes using the first structure (1410) and the second structure (1410) to isolate a portion of the semiconductor device (1200) for the bit line implant.
Abstract:
A method of manufacturing an integrated circuit is provided with a semiconductor substrate (506) having a core region (502) and a periphery region (504). A charge-trapping dielectric layer (510) is deposited in the core region (502), and a gate dielectric layer (522) is deposited in the periphery region (504). Bitlines (518) are formed in the semiconductor substrate (506) in the core region (502) and not in the periphery region (504). A wordline-gate layer (524) is formed and implanted with dopant in the core region (502) and not in the periphery region (504). A wordline (528) and gate (530) are formed. Source/drain junctions are implanted with dopant in the semiconductor substrate (506) around the gate (530), and the gate (530) is implanted with a gate doping implantation in the periphery region (504) and not in the core region (502).
Abstract:
A method for transferring a reduced lithographic image size pattern onto a film (14) on a substrate (12) is disclosed. A photosensitive material having an opening (20) of a minimum size achievable by the limits of lithography is transferred onto a mask layer (16) on a substrate (12) having a film (14) thereon. Reduction in the image size is achieved by establishing sidewalls (28) to the interior vertical surfaces (26) of the opening of the mask layer (16) by depositing a conformal layer (28), followed by anisotropic etching. The dimension of the opening (24) is reduced by the combined thickness of the two opposite sidewalls (28). An anisotropic etching of the film (14) transfers a pattern of openings (30) of a minimum size smaller than possible by lithography.
Abstract:
One aspect of the present invention provides a process for forming IC devices (100) with ESD protection transistors (112). According to one aspect of the invention, an ESD protection transistor (112) is provided with a light doping and then, after forming spacers, a heavy doping. The heavy doping with spacers in place can lower the sheet resistance, enhance the bipolar effect for the transistor, reduce the transistor's capacitance, and reduce the junction breakdown voltage, all without causing short channel effects. The invention thereby provides ESD protection transistors (112) that are compact, highly sensitive, and fast-switching. The spacers can be formed at the same time as spacers for other transistors, such as other transistors in a peripheral region of the device (100).
Abstract:
A method of forming a non-volatile semiconductor memory device, involving forming a charge trapping dielectric (114) over a substrate (112); forming a first set of memory cell gates (116) over the charge trapping dielectric (114) in a core region; forming a conformal insulation material layer (118) around the first set of memory cell gates (116); and forming a second set of memory cell gates (122) in the core region, wherein each memory cell gate of the second set of memory cell gates (122) is adjacent to at least one memory cell gate of the first set of memory cell gates (116), each memory cell gate of the first set of memory cell gates (116) is adjacent at least one memory cell gate of the second set of memory cell gates (122), and the conformal insulation material layer (118) is positioned between each adjacent memory cell gate is disclosed.
Abstract:
One aspect of the present invention provides a process for forming IC devices (100) with ESD protection transistors (112). According to one aspect of the invention, an ESD protection transistor (112) is provided with a light doping and then, after forming spacers, a heavy doping. The heavy doping with spacers in place can lower the sheet resistance, enhance the bipolar effect for the transistor, reduce the transistor's capacitance, and reduce the junction breakdown voltage, all without causing short channel effects. The invention thereby provides ESD protection transistors (112) that are compact, highly sensitive, and fast-switching. The spacers can be formed at the same time as spacers for other transistors, such as other transistors in a peripheral region of the device (100).
Abstract:
The present invention facilitates programming of selected floating gate devices while successfully inhibiting the programming of unselected devices, without the need for growing multiple thicknesses of oxides. The preferred embodiment of the present invention utilizes a multiple select gate device. In particular, the select gate device is preferably a dual floating gate device rather than the conventional transistor (or device functioning as a conventional transistor) used in the current Flash memory systems as a select gate device.
Abstract:
A system (600, 800) is disclosed for producing an indication (679) of the logical state of a flash memory cell (866) for virtual ground flash memory (640) operations. The system (600, 800) comprises a bit line precharge and hold circuit (660, 855) which is operable to apply and maintain a source terminal voltage (859) ( e.g. , about 0 volts, ground) to a bit line (850) associated with the source terminal (857) of a cell adjacent (856) to the cell which is sensed (866) during a read operation, wherein the applied source terminal voltage is substantially the same as the bit line virtual ground voltage (869) applied to the source terminal bit line (860) of the selected memory cell (866) to be sensed. The system (600, 800) also includes a drain bit line circuit (650, 875) operable to generate a drain terminal voltage (615, 815) for a drain terminal (868) of a selected memory cell (866) to be sensed. The system (600, 800) further includes a selective bit line decode circuit (652) which is operable to select the bit lines (860, 870) of a memory cell (866) to be sensed and the bit line (850) of an adjacent cell (856), and a core cell sensing circuit (695, 890) which is operable to sense a core cell sense current (675) at a bit line associated with a source terminal (867) of the selected memory cell (866) to be sensed during memory read operations, and produce an indication (679) of the flash memory cell logical state, which is substantially independent of charge sharing leakage current to an adjacent cell.