摘要:
A method of forming bit line aligned to a phase change material that includes forming a pedestal of a sacrificial material on a portion of a lower electrode and fowling at least one dielectric material adjacent to the sacrificial material, wherein the at least one dielectric material has an upper surface substantially coplanar with an upper surface of the pedestal of the sacrificial material. The pedestal of the sacrificial material is removed selective to the at least one dielectric material and the lower electrode to provide an opening to an exposed surface of the lower electrode. A phase change material is formed on the exposed surface of the lower electrode, and the opening is filled with a conductive fill material. A self-aligned etch back process is also provided.
摘要:
Phase change memory devices and methods for operating described herein are based on the discovery that, following an initial high current operation applied to a phase change memory cell to establish the high resistance reset state, the current-voltage (I-V) behavior of the memory cell under different bias voltages can be used to detect if the memory cell is a defect cell having poor data retention characteristics.
摘要:
An array of phase change memory cells is manufactured by forming a separation layer over an array of contacts, forming a patterning layer on the separation layer and forming an array of mask openings in the patterning layer using lithographic process. Etch masks are formed within the mask openings by a process that compensates for variation in the size of the mask openings that result from the lithographic process. The etch masks are used to etch through the separation layer to define an array of electrode openings exposing the underlying contacts. Electrode material is deposited within the electrode openings; and memory elements are formed over the bottom electrodes. Finally, bit lines are formed over the memory elements to complete the memory cells. In the resulting memory array, the critical dimension of the top surface of bottom electrode varies less than the width of the memory elements in the mask openings.
摘要:
A memory cell structure and method for forming the same. The method includes forming a pore within a dielectric layer. The pore is formed over the center of an electrically conducting bottom electrode. The method includes depositing a thermally insulating layer along at least one sidewall of the pore. The thermally insulating layer isolates heat from phase change current to the volume of the pore. In one embodiment phase change material is deposited within the pore and the volume of the thermally insulating layer. In another embodiment a pore electrode is formed within the pore and the volume of the thermally insulating layer, with the phase change material being deposited above the pore electrode. The method also includes forming an electrically conducting top electrode above the phase change material.
摘要:
A memory cell structure and method to form such structure. The method partially comprised of forming a via within an oxidizing layer, over the center of a bottom electrode. The method includes depositing a via spacer along the sidewalls of the via and oxidizing the via spacer. The via spacer being comprised of a material having a Pilling-Bedworth ratio of at least one and one-half and is an insulator when oxidized. The via area is reduced by expansion of the via spacer during the oxidation. Alternatively, the method is partially comprised of forming a via within a first layer, over the center of the bottom electrode. The first layer has a Pilling-Bedworth ratio of at least one and one-half and is an insulator when oxidized. The method also includes oxidizing at least a portion of the sidewalls of the via in the first layer.
摘要:
Vertical field effect transistor semiconductor structures and methods for fabrication of the vertical field effect transistor semiconductor structures provide an array of semiconductor pillars. Each vertical portion of each semiconductor pillar in the array of semiconductor pillars has a linewidth greater than a separation distance to an adjacent semiconductor pillar. Alternatively, the array may comprise semiconductor pillars with different linewidths, optionally within the context of the foregoing linewidth and separation distance limitations. A method for fabricating the array of semiconductor pillars uses a minimally photolithographically dimensioned pillar mask layer that is annularly augmented with at least one spacer layer prior to being used as an etch mask.
摘要:
A method for fabricating a phase change memory device including memory cells includes patterning a via to a contact surface of a substrate corresponding to each of an array of conductive contacts to be connected to access circuitry, lining each via with a conformal conductive seed layer to the contact surface, forming a dielectric layer covering the conductive seed layer, and etching a center region of each via to the contact surface to expose the conformal conductive seed layer at the contact surface. The method further includes electroplating phase change material on exposed portions of the conformal conductive seed layer, recessing the phase change material within the center region forming a conductive material that remains conductive upon oxidation, on the recessed phase change material, oxidizing edges of the conformal conductive seed layer formed along sides of each via, and forming a top electrode over each memory cell.
摘要:
Systems, methods, and devices for iteratively writing contents to memory locations are provided. A statistical model is used to determine a sequence of pulses to write desired contents to a memory location. The contents can be expressed as a resistance value in a range to store one or more bits in a memory cell. For phase change memory, an adaptive reset pulse and one or more annealing pulses are selected based on a desired resistance range. Reading the resistance value of the memory cell can provide feedback to determine adjustments in an overall pulse application strategy. The statistical model and a look up table can be used to select and modify pulses. Adaptively updating the statistical model and look up table may reduce the number of looping iterations to shift the resistance value of the memory cell into the desired resistance range.
摘要:
Vertical field effect transistor semiconductor structures and methods for fabrication of the vertical field effect transistor semiconductor structures provide an array of semiconductor pillars. Each vertical portion of each semiconductor pillar in the array of semiconductor pillars has a linewidth greater than a separation distance to an adjacent semiconductor pillar. Alternatively, the array may comprise semiconductor pillars with different linewidths, optionally within the context of the foregoing linewidth and separation distance limitations. A method for fabricating the array of semiconductor pillars uses a minimally photolithographically dimensioned pillar mask layer that is annularly augmented with at least one spacer layer prior to being used as an etch mask.
摘要:
A key hole structure and method for forming a key hole structure to form a pore in a memory cell. The method includes forming a first dielectric layer on a semiconductor substrate having an electrode formed therein, forming an isolation layer on the first dielectric layer, forming a second dielectric layer on the isolation layer, and forming a planarization stop layer on the second dielectric layer. The method further includes forming a via to extend to the first dielectric layer and recessing the isolation layer and the stop layer with respect to the second dielectric layer, depositing a conformal film within via and over the stop layer, forming a key hole within the conformal film at a center region of the via such that a tip of the key hole is disposed at an upper surface of the second dielectric layer, and planarizing the conformal film to the stop layer.