Abstract:
A multi-level cell NOR flash memory device includes a plurality of gate lines, a plurality of source regions, a plurality of drain regions, a plurality of source lines, a plurality of bitlines, and a plurality of power lines. The bitlines each have a specific sheet resistance. A specific number of the bitlines are disposed between two adjacent ones of the power lines. Accordingly, the multi-level cell NOR flash memory device is of a high transconductance and uniformity and thereby features an enhanced conforming rate.
Abstract:
In a method of manufacturing a non-volatile memory cell, a self-aligned metal silicide is used in place of a conventional tungsten metal layer to form a polysilicon gate, and the self-aligned metal silicide is used as a connection layer on the polysilicon gate. By using the self-aligned metal silicide to form the polysilicon gate, the use of masks in the etching process may be saved to thereby enable simplified manufacturing process and accordingly, reduced manufacturing cost. Meanwhile, the problem of resistance shift caused by an oxidized tungsten metal layer can be avoided.
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:
A method for forming a memory device is provided. A nitride layer is formed over a substrate. The nitride layer and the substrate are etched to form a trench. The nitride layer is trimmed on opposite sides of the trench to widen the trench within the nitride layer. The trench is filled with an oxide material. The nitride layer is stripped from the memory device, forming a mesa above the trench.
Abstract:
In a method of manufacturing a double-implant NOR flash memory structure, a phosphorus ion implantation process is performed, so that a P-doped drain region is formed in a semiconductor substrate between two gate structures to overlap with a highly-doped drain (HDD) region and a lightly-doped drain (LDD) region. Therefore, the electric connection at a junction between the HDD region and the LDD region is enhanced and the carrier mobility in the memory is not lowered while the problems of short channel effect and punch-through of LDD region are solved.
Abstract:
A semiconductor structure with stress regions includes a substrate defining a first and a second device zone; a first and a second stress region formed in each of the first and second device zones to yield stress different in level; and a barrier plug separating the two device zones from each other. Due to the stress yielded at the stress regions, increased carrier mobility and accordingly, increased reading current can be obtained, and a relatively lower reading voltage is needed to obtain initially required reading current. As a result, the probability of stress-induced leakage current (SILC) is reduced and the semiconductor memory structure may have enhanced data retention ability.
Abstract:
A single-poly non-volatile memory includes a storing node, a control node and a floating gate. While a programming operation is executed, a bit line is provided with a low voltage and a control line is provided with a high voltage so that a coupling voltage occurs in the floating gate. The voltage difference between the floating gate and the storing node is able to send electrons into the floating gate, but the voltage difference between the floating gate and the control node is not enough to expel electrons from the floating gate. While an erasing operation is executed, a bit line is provided with a high voltage and a control line is provided with a low voltage so that a coupling voltage occurs on the floating gate. The voltage difference between the floating gate and the storing node is able to expel electrons from the floating gate, but the voltage difference between the floating gate and the control node is not enough to send electrons into the floating gate.
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.