Abstract: Semiconductor memory devices and methods to fabricate thereof are described. A first gate base is formed on a first insulating layer on a substrate. A first gate fin is formed on the first gate base. The first gate fin has a top and sidewalls. Next, a second insulating layer is formed on the top and sidewalls of the first gate fin and portions of the first gate base. A second gate is formed on the second insulating layer. Source and drain regions are formed in the substrate at opposite sides of the first gate base. In one embodiment, the first gate fin includes an undoped polysilicon and the first gate base includes an n-type polysilicon. In another embodiment, the first gate fin includes an undoped amorphous silicon and the first gate base includes an n-type amorphous silicon.

Abstract: An ovonic threshold switch may be formed of a continuous chalcogenide layer. That layer spans multiple cells, forming a phase change memory. In other words, the ovonic threshold switch may be formed of a chalcogenide layer which extends, uninterrupted, over numerous cells of a phase change memory.

Abstract: According to an embodiment of the invention, a flash memory cell includes a first gate stack and a second gate stack having a film deposited across the gap between the first and second gate stacks so that the film creates a void between the first and second gate stacks. Dielectric materials may be used to reduce conductivity between the two stacks. A dielectric material that is resistant to conductivity has a low dielectric constant (k). The lowest-k dielectric material is air, which has a dielectric constant of approximately 1. By creating a void between the two gate stacks, the least conductive material (air) is left filling the space between the gate stacks, and the likelihood of parasitic coupling of two adjacent floating gates is substantially reduced.

Abstract: A phase change material may be formed within a trench in a first layer to form a damascene memory element and in an overlying layer to form a threshold device. Below the first layer may be a wall heater. The wall heater that heats the overlying phase change material may be formed in a U-shape in some embodiments of the present invention. The phase change material for the memory element may be elongated in one direction to provide greater alignment tolerances with said heater and said threshold device.

Abstract: A phase change material may be formed within a trench in a first layer to form a damascene memory element and in an overlying layer to form a threshold device. Below the first layer may be a wall heater. The wall heater that heats the overlying phase change material may be formed in a U-shape in some embodiments of the present invention. The phase change material for the memory element may be elongated in one direction to provide greater alignment tolerances with said heater and said threshold device.

Abstract: A dual resistance heater for a phase change material region is formed by depositing a resistive material. The heater material is then exposed to an implantation or plasma which increases the resistance of the surface of the heater material relative to the remainder of the heater material. As a result, the portion of the heater material approximate to the phase change material region is a highly effective heater because of its high resistance, but the bulk of the heater material is not as resistive and, thus, does not increase the voltage drop and the current usage of the device.

Abstract: According to an embodiment of the invention, a flash memory cell includes a first gate stack and a second gate stack having a film deposited across the gap between the first and second gate stacks so that the film creates a void between the first and second gate stacks. Dielectric materials may be used to reduce conductivity between the two stacks. A dielectric material that is resistant to conductivity has a low dielectric constant (k). The lowest-k dielectric material is air, which has a dielectric constant of approximately 1. By creating a void between the two gate stacks, the least conductive material (air) is left filling the space between the gate stacks, and the likelihood of parasitic coupling of two adjacent floating gates is substantially reduced.

Abstract: A phase change material may be formed within a trench in a first layer to form a damascene memory element and in an overlying layer to form a threshold device. Below the first layer may be a wall heater. The wall heater that heats the overlying phase change material may be formed in a U-shape in some embodiments of the present invention. The phase change material for the memory element may be elongated in one direction to provide greater alignment tolerances with said heater and said threshold device.

Abstract: A phase change memory may be formed to have a dimension that is sub-lithographic in one embodiment by forming a surface feature over the phase change material, and coating the surface feature with a mask of sub-lithographic dimensions. The horizontal portions of the mask and the surface feature may then be removed and the remaining portions of the mask may be used to define a dimension of said phase change material. Another dimension of the phase change material may be defined using an upper electrode extending over said phase change material as a mask to etch the phase change material.

Abstract: A method of fabricating a flash memory integrated circuit is described. In an embodiment of the present invention a dielectric filled trench isolation region is formed in a silicon substrate. The dielectric filled trench isolation region isolates a first portion of the silicon substrate from a second portion of the silicon substrate. A portion of the dielectric in the trench is then removed to reveal a portion of the silicon substrate in the trench between the first and second portions of the silicon substrate. Ions are then implanted to form a first source region in the first portion of the silicon substrate and to form a second source region in the second portion of the silicon substrate and to form a doped region in the revealed silicon substrate in the trench wherein the doped region in the trench extends from the first doped source region to the second doped source region.

Abstract: A method of fabricating a flash memory integrated circuit is described. In an embodiment of the present invention a dielectric filled trench isolation region is formed in a silicon substrate. The dielectric filled trench isolation region isolates a first portion of the silicon substrate from a second portion of the silicon substrate. A portion of the dielectric in the trench is then removed to reveal a portion of the silicon substrate in the trench between the first and second portions of the silicon substrate. Ions are then implanted to form a first source region in the first portion of the silicon substrate and to form a second source region in the second portion of the silicon substrate and to form a doped region in the revealed silicon substrate in the trench wherein the doped region in the trench extends from the first doped source region to the second doped source region.