Abstract:
A method of fabricating a memory device is described. During the process of forming the memory cell area and the periphery area of a semiconductor device a photoresist layer is formed on the memory cell area before the spacers are formed on the sidewalls of the gates. Therefore, the memory cell area is prevented from being damaged to mitigate the leakage current problem during the process of forming spacers in the periphery circuit area.
Abstract:
A method and device for avoiding oxide gouging in shallow trench isolation (STI) regions of a semiconductor device. A trench may be etched in an STI region and filled with insulating material. An anti-reflective coating (ARC) layer may be deposited over the STI region and extend beyond the boundaries of the STI region. A portion of the ARC layer may be etched leaving a remaining portion of the ARC layer over the STI region and extending beyond the boundaries of the STI region. A protective cap may be deposited to cover the remaining portion of the ARC layer as well as the insulating material. The protective cap may be etched back to expose the ARC layer. However, the protective cap still covers and protects the insulating material. By providing a protective cap that covers the insulating material, gouging of the insulating material in STI regions may be avoided.
Abstract:
A method of fabricating a memory device is described. During the process of forming the memory cell area and the periphery area of a semiconductor device a photoresist layer is formed on the memory cell area before the spacers are formed on the sidewalls of the gates. Therefore, the memory cell area is prevented from being damaged to mitigate the leakage current problem during the process of forming spacers in the periphery circuit area.
Abstract:
The present invention provides a flash memory device and method for making the same having a floating gate structure with a semiconductor substrate and shallow trench isolation (STI) structure formed in the substrate. A first polysilicon layer is formed over the substrate and the STI structure. The recess formed within the first polysilicon layer is over the STI structure and extends through the first polysilicon layer to the STI structure. An oxide fill is provided within the recess and is etched back. ONO (oxide-nitride-oxide) layer conformally covers the oxide fill and the first polysilicon layer. The second polysilicon layer covers the ONO layer. The oxide fill within the recess provides a minimum spacing between the second polysilicon layer and the corner of the STI regions, thereby avoiding the creation of a weak spot and reducing the risk of gate breakdown, gate leakage, and improving device reliability.
Abstract:
Methods are disclosed for fabricating dual bit SONOS flash memory cells, comprising forming polysilicon gate structures over an ONO layer, and doping source/drain regions of the substrate using the gate structures as an implant mask. Methods are also disclosed in which dielectric material is formed over and between the gate structures, and the wafer is planarized using an STI CMP process to remove dielectric material over the polysilicon gate structures.
Abstract:
A method for repairing an isolation dielectric damaged during a semiconductor fabrication process is disclosed in which a hard mask material is used to pattern a first material, the first material having openings therein exposing isolation regions comprising a first isolation dielectric layer. The method includes etching the hard mask material from the first material, wherein the etch creates gouges in the first isolation dielectric layer, and depositing a second layer of isolation dielectric over the first material, wherein the second isolation dielectric layer fills the gouges in the first isolation dielectric layer. The method further includes polishing on the second layer of isolation dielectric to remove the second layer of isolation dielectric from the first material.
Abstract:
One aspect of the present invention relates to a method of forming a non-volatile semiconductor memory device, involving the sequential or non-sequential steps of forming a charge trapping dielectric over a substrate, the substrate having a core region and a periphery region; removing at least a portion of the charge trapping dielectric in the periphery region; forming a gate dielectric in the periphery region; forming buried bitlines in the core region; and forming gates in the core region and the periphery region.
Abstract:
A system and methodology is provided for verifying erasure of one or more dual bit virtual ground memory cells in a memory device, such as a flash memory. Each of the dual bits have a first or normal bit and a second or complimentary bit associated with the first or normal bit. The system and methodology include verifying and erasure of both a normal bit and a complimentary bit of the cell. The erasure includes applying a set of erase pulses to the normal bit and complimentary bit in a single dual bit cell. The set of erase pulses is comprised of a two sided erase pulse to both sides of the bits in the cell or transistor junction followed by a first single sided erase pulse to one side and a second single sided erase pulse to the other side of transistor junction.
Abstract:
One aspect of the present invention relates to a method of forming a SONOS type non-volatile semiconductor memory device, involving forming a first layer of a charge trapping dielectric on a semiconductor substrate; forming a second layer of the charge trapping dielectric over the first layer of the charge trapping dielectric on the semiconductor substrate; optionally at least partially forming a third layer of the charge trapping dielectric over the second layer of the charge trapping dielectric on the semiconductor substrate; optionally removing the third layer of the charge trapping dielectric; forming a source/drain mask over the charge trapping dielectric; implanting a source/drain implant through the charge trapping dielectric into the semiconductor substrate; optionally removing the third layer of the charge trapping dielectric; and one of forming the third layer of the charge trapping dielectric over the second layer of the charge trapping dielectric on the semiconductor substrate, reforming the third layer of the charge trapping dielectric over the second layer of the charge trapping dielectric on the semiconductor substrate, or forming additional material over the third layer of the charge trapping dielectric.
Abstract:
A predetermined species such as nitrogen is placed at an interface between a bit line junction and a dielectric layer of a control dielectric structure of a flash memory device to minimize degradation of such an interface by minimizing formation of interface defects during program or erase operations of the flash memory device. The predetermined species such as nitrogen is implanted into a bit line junction of the flash memory device. A thermal process is performed that heats up the semiconductor wafer such that the predetermined species such as nitrogen implanted within the semiconductor wafer thermally drifts to the interface between the bit line junction and the control dielectric structure during the thermal process. The predetermined species such as nitrogen at the interface minimizes formation of interface defects and thus degradation of the interface with time during the program or erase operations of the flash memory device.