Abstract:
Memory cells including cell cores having free regions are disclosed. The free regions exhibit a strain that affects a magnetization orientation within the cell core. A stressor structure may exert a stress upon at least a portion of the cell core to effect the strain state of the free region. Also disclosed are semiconductor device structures and systems including such memory cells as well as methods for forming such memory cells.
Abstract:
A method of fabricating a shared element semiconductor structure in which the insulating layer of a silicon-on-insulator structure is patterned to form a gate oxide. The bulk semiconductor underlying the insulating layer is defined into an FET (field-effect transistor) with its gate region below the gate oxide. The epitaxial layer above the insulating layer is defined into another FET with its drain region above the gate oxide, whereby the drain region also operates as the gate electrode for the bulk FET. Also described is a method of forming a silicon on insulator substrate with insulating layer usable as a gate oxide by means of bonding a silicon substrate to an oxidized epitaxial layer on another silicon seed substrate and then removing the seed substrate.
Abstract:
Methods of forming memory cells, magnetic memory cell structures, and arrays of magnetic memory cell structures are disclosed. Embodiments of the methods include patterning a precursor structure to form a stepped structure including at least an upper discrete feature section and a lower feature section with a broader width, length, or both than the upper discrete feature section. The method uses patterning acts directed along a first axis, e.g., an x-axis, and then along a second axis, e.g., a y-axis, that is perpendicular to or about perpendicular to the first axis. The patterning acts may therefore allow for more unifoimity between a plurality of formed, neighboring cell core structures, even at dimensions below about thirty nanometers. Magnetic memory structures and memory cell arrays are also disclosed.
Abstract:
Memory cells are disclosed. Magnetic regions within the memory cells include an alternating structure of magnetic sub-regions and coupler sub-regions. The coupler material of the coupler sub-regions antiferromagnetically couples neighboring magnetic sub-regions and effects or encourages a vertical magnetic orientation exhibited by the neighboring magnetic sub-regions. Neighboring magnetic sub-regions, spaced from one another by a coupler sub-region, exhibit oppositely-directed magnetic orientations. The magnetic and coupler sub-regions may each be of a thickness tailored to form the magnetic region in a compact structure. Interference between magnetic dipole fields emitted from the magnetic region on switching of a free region in the memory cell may be reduced or eliminated. Also disclosed are semiconductor device structures, spin torque transfer magnetic random access memory (STT-MRAM) systems, and methods of fabrication.
Abstract:
Described herein is a reference voltage circuit which includes, in combination, a bit line and first and second word line reference transistors connected to the bit line and operative to be turned on with a reference pulse simultaneously with the turning on of the word lines in the main memory circuit. First and second ferroelectric capacitors are connected to each of the first and second word line reference transistors, respectively, and to a source of plate line switching voltage, and a first precharging transistor is connected between the first ferroelectric capacitor and ground potential. A second precharging transistor is connected between the second ferroelectric capacitor and a further source of switching voltage, so that the first and second ferroelectric capacitors are polarized in a ONE and ZERO state in the manner identical to the logic states of the ferroelectric capacitors in the main ferroelectric memory circuit. Thus, when the first and second word line reference transistors turn on, the bit line reference voltage is raised above ground potential by the sum of the voltages of the first and second ferroelectric capacitors. This in turn causes the bit line reference voltage, BL, to track the voltage variations of the ferroelectric capacitors in the main memory circuit, thus providing improved margins for the BL and BL complementary signals which are sensed by a plurality of sense amplifiers for the main memory circuit.
Abstract:
Described herein is a reference voltage circuit which includes, in combination, a bit line and first and second word line reference transistors connected to the bit line and operative to be turned on with a reference pulse simultaneously with the turning on of the word lines in the main memory circuit. First and second ferroelectric capacitors are connected to each of the first and second word line reference transistors, respectively, and to a source of plate line switching voltage, and a first precharging transistor is connected between the first ferroelectric capacitor and ground potential. A second precharging transistor is connected between the second ferroelectric capacitor and a further source of switching voltage, so that the first and second ferroelectric capacitors are polarized in a ONE and ZERO state in the manner identical to the logic states of the ferroelectric capacitors in the main ferroelectric memory circuit. Thus, when the first and second word line reference transistors turn on, the bit line reference voltage is raised above ground potential by the sum of the voltages of the first and second ferroelectric capacitors. This in turn causes the bit line reference voltage, BL, to track the voltage variations of the ferroelectric capacitors in the main memory circuit, thus providing improved margins for the BL and BL complementary signals which are sensed by a plurality of sense amplifiers for the main memory circuit.
Abstract:
A method of forming isolation trenches in CMOS integrated circuits is disclosed. The trench side walls are covered by a thin oxide layer, and the trenches are filled with a highly doped polysilicon. The doped polysilicon has a high work function which prevents oxide charges from inverting the trench side walls and thereby turns off the parasitic transistors at these side walls to reduce latchup.
Abstract:
A process for making a CMOS dual-well semiconductor structure with field isolation doping, wherein only a single lithographic masking step is required for providing self-alignment both of the wells to each other and also of the field isolation doping regions to the wells. The lithographic masking step forms a well mask and defines an oxidation barrier which acts as: an implant mask (absorber) during the ion-implantation of a field dopant of one type; an oxidation barrier over one well during the oxidation of the opposite-type well to form over the one well a sacrificial oxide layer which forms the alignment marks for subsequent formation of the field-doping regions; and a dopant-transmitter during the ion-implantation of an opposite-type field dopant which is simultaneously absorbed by the sacrificial oxide. As a result, there are formed field-doped oxide layers self-aligned to the wells so that, with a subsequent masking step, oxide field isolations are defined over the doped oxide layers. A heat cycle is then used to drive the field dopants into the corresponding field-doping regions.