Abstract:
A short channel metal oxide semiconductor transistor device is processed without undesirable short channel effects, such as V.sub.T falloff and with a reasonable source-drain operating voltage support. In a substrate lightly doped with P-type conductivity material and source and drain region heavily doped with an N-type conductivity material, two lightly doped N- regions are disposed between the edge of the gate and the source and drain regions. A channel region is more heavily doped with P-type material than the substrate. Two regions extend from opposite sides of the channel region to an area generally below the two N- regions and above the substrate, which regions are more heavily doped than the channel regions.
Abstract:
A method for making a CMOS integrated circuit device saves on masking steps by using unmasked blanket implantations at various steps of the process, such as setting the threshold voltages of the transistors, forming a lightly doped drain for the N-channel transistor, and for forming the source/drain regions of the N-type transistor.
Abstract:
A CMOS device architecture which includes substrate-gated inverted PMOS transistors, as well as bulk NMOS. The inverted-PMOS channels are formed in a different layer from the NMOS gates, and these layers may even have different compositions. Moreover, the NMOS and inverted-PMOS devices have different gate oxide layers, so the thicknesses can be independently optimized. The drain underlap of the inverted device is defined by a patterning step, so it can be increased for high-voltage operation if desired.
Abstract:
A method for substantially reducing variations in a programming voltage of an anti-fuse structure formed on an integrated circuit wafer. The anti-fuse structure has a metal-one layer, an anti-fuse layer disposed above the metal-one layer, a oxide layer disposed above the anti-fuse layer, and a via hole in the oxide layer through to the anti-fuse layer for receiving a deposition of a metal-two material. The method includes the step of rendering a selected anti-fuse area susceptible to fuse link formation by reducing a resistivity of the selected anti-fuse area to diffusion of atoms from one of the metal-one layer and the metal-two layer when a programming voltage is applied between the metal one layer and the metal two layer. The selected anti-fuse area is located in the anti-fuse layer and substantially adjacent to and outside of an anti-fuse area directly below the via hole. The method further includes the step of depositing the metal-two material into the via hole.
Abstract:
A CMOS SRAM cell has a polycrystalline silicon signal line between a common node, which is the data storage node, and the power supply. A field effect device is fabricated within this polycrystalline silicon signal line. The channel of the field effect device is separated from an active area in the substrate by a thin gate dielectric, and the active region within the substrate functions as the control gate for the field effect device. Such a device can be used to provide polycrystalline silicon P-channel transistors for use in CMOS SPRAM cells.
Abstract:
Field oxide regions are formed between active regions of a silicon substrate by forming over the substrate a sandwich of silicon dioxide, silicon nitride and silicon dioxide layers, opening the layers to expose a portion of the silicon substrate, removing a layer of the exposed substrate, forming side wall spacers on the edges of the opening, removing a layer of the silicon substrate exposed between the side wall spacers, and then reaching the exposed substrate for the thermal oxidation of the exposed substrate for forming the field oxide region. In those structures in which the field oxide is buried in the substrate as shown in FIG. 12, it may be feasible to use thicker field oxide regions and thereby to reduce the need for the heavily doped surface layer under the field oxide.
Abstract:
A short channel metal oxide semiconductor transistor device is processed without undesirable short channel effects, such as V.sub.T falloff and with a reasonable source-drain operating voltage support. In a substrate lightly doped with P-type conductivity material and source and drain region heavily doped with an N-type conductivity material, two lightly doped N- regions are disposed between the edge of the gate and the source and drain regions. A channel region is more heavily doped with P-type material than the substrate. Two regions extend from opposite sides of the channel region to an area generally below the two N- regions and above the substrate, which regions are more heavily doped than the channel regions.
Abstract:
A method for fabrication of metal to semiconductor contacts results in sloped sidewalls in contact regions. An oxide layer is deposited and etched back to form sidewall spacers. A glass layer is then deposited and heated to reflow. After reflow, an etch back of the glass layer results is sloped sidewalls at contact openings and over steps.
Abstract:
An antifuse structure includes a first electrode, a layer of enhanced amorphous silicon over the first electrode, and a second electrode over the layer of enhanced amorphous silicon. The layer of enhanced amorphous silicon is formed by an ion-implantation of a neutral species and a dopant species into a deposited layer of amorphous silicon, such that the antifuse structure will have a stable conductive link in a programmed state and such that it will be less susceptible to off-state leakage in an unprogrammed state. A method for making an antifuse structure includes forming a lower electrode, depositing an amorphous silicon layer over the lower electrode, ion-implanting a neutral species and a dopant species into the amorphous silicon layer, and forming an upper electrode over the amorphous silicon layer.
Abstract:
A computer-aided method and system are provided for obtaining a measurement of the capacitance value of a device under test (DUT). The complex impedance of a device under test (DUT) is measured at two nearby frequencies using an RLC meter. The two complex impedance values are then stored in a computer readable medium. The DUT is modeled by a programmed computer as a four element RLC model circuit including a resistor and inductor in series with a parallel RC circuit having a single capacitor which represents the capacitance of the DUT. Four equations which describe the electrical characteristics of the four element RLC model circuit are stored in a computer readable medium. The four measured values of complex impedance are substituted by the computer into the four stored equations. Values are obtained for the four individual RLC circuit elements by solving the four equations. The four unknown values are obtained by use of an optimization routine and then stored to a computer readable medium. The value capacitor element representing the capacitance of the DUT is then displayed.