Abstract:
A manufacturing method for a MirrorBit® Flash memory includes providing a semiconductor substrate [102] [602] and depositing a charge-trapping dielectric layer [504] [606]. First and second bitlines [512] [608] are implanted and a wordline layer [515] is deposited [610]. A hard mask layer [516] is deposited over the wordline layer [515] [612]. The hard mask layer [516] is of a material formulated for removal without damaging the charge-trapping dielectric layer [504]. A photoresist [518] is deposited over the wordline layer [515] and used to form a hard mask [519] [618]. The photoresist [518] is removed [620]. The wordline layer [515] is processed using the hard mask [519] to form a wordline [525-528].
Abstract:
A memory device (100) includes a conductive structure (210), a number of dielectric layers (410430) and a control gate (510). The dielectric layers (410-430) are formed around the conductive structure (210) and the control gate (510) is formed over the dielectric layers (410-430). A portion of the conductive structure (210) functions as a drain region (1005) for the memory device (100) and at least one of the dielectric layers (410-430) functions as a charge storage structure for the memory device (100). The dielectric layers (410-430) may include oxide-nitride-oxide layers.
Abstract:
A system and methodology is provided for verifying erasure of one or more dual bit virtual ground memory cells (10, 82, 84, 86, 88) in a memory device, such as a flash memory. Each of the dual bits (10, 82, 84, 86, 88) has 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:
A method for removing a hard mask (26') during a semiconductor fabrication process is disclosed in which a hard mask (26') material is used to pattern a first material (20). The method includes a two-step removal process that includes performing a major wet etch to remove a majority of the hard mask (26') material, followed by performing a minor dry etch that removes a remainder of the hard mask (26') material.
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, if present; 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, if present; 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 method for forming a memory device ( 100) is provided. A nitride layer (330) is formed over a substrate (310). The nitride layer (330) and the substrate (310) are etched to form a trench (510). The nitride layer (330) is trimmed on opposite sides of the trench (510) to widen the trench (510) within the nitride layer (330). The trench (510) is filled with an oxide material (810). The nitride layer (330) is stripped from the memory device (100), forming a mesa (1410) above the trench (510).
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 relates to a non-volatile semiconductor memory device, containing a substrate (12); a charge trapping dielectric (14) over the core region of the substrate (12); a gate dielectric in the periphery region of the substrate (12); buried bitlines (26) under the charge trapping dielectric (14) in the core region; and wordlines (28) over the charge trapping dielectric (14) in the core region, wherein the core region is substantially planar. Another aspect of the present invention relates to a method of forming a non-volatile semiconductor memory device, involving sequentially or non-sequentially forming a charge trapping dielectric (14) over a substrate (12); removing at least a portion of the charge trapping dielectric (14) in the periphery region (18); forming a gate dielectric (22) in the periphery region (18); forming buried bitlines (26) in the core region (16); and forming gates (28) in the core region (16) and the periphery region (18).
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:
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 (14) over a substrate (12), the substrate (12) having a core region (16) and a periphery region (18); removing at least a portion of the charge trapping dielectric (14) in the periphery region (18); forming a gate dielectric (22) in the periphery region (18); forming buried bitlines (26) in the core region (16); and forming gates (28) in the core region (16) and the periphery region (18).