Vlsi Technology, Inc.

Sgs-thomson Microelectronics Limited

Stmicroelectronics Gmbh

Mostek Corporation

Koninklijke Philips Corporation N.v.

Thomson Components-mostek Corporation

Yu-Pin Han

Tsiu Chiu Chan

Ying-Tsong Loh

Fu-Tai Liou

Ivan Sanchez

Elmer H Guritz

Frank R Bryant

Koucheng Wu

Richard A Blanchard

Robert O Miller

Landon B Vines

Felix H Fujishiro

Mohammed M Farohani

Miguel A Delgado

Walter D Parmantie

Samuel J Nagalingam

Bing C Ma

In the manufacture of an integrated circuit, contaminated oxide is replaced by relatively pure oxide using the following steps. First, a partially manufactured integrated circuit is bathed in an aqueous solution of hydrogen peroxide and ammonium hydroxide to oxidize organic materials and weaken bonds of metal contaminants to the integrated circuit substrate. Second, an aqueous rinse removes the oxidized organic materials and metal contaminants. Third, the integrated circuit is bathed in an aqueous solution of hydrogen fluoride and nitric acid. The hydrogen fluroide etches the contaminated oxide; the nitric acid combines with calcium and metal contaminants freed as the oxide is etched. The resulting nitride byproducts are highly soluble and easily removed in the following aqueous rinse. A drying step removes rinse water from the integrated circuit. Finally, an oxide formation step provides a relatively pure oxide layer. In the case of a gate oxide, the method removes a sacrificial oxide in preparation for gate oxide growth. In the case of formation of the submetal dielectric, oxide formation involves an TEOS oxide deposition. A key advantage of the invention is the improved calcium removal due to the nitric acid.

Integrated circuit manufacture method with aqueous hydrogen fluoride and nitric acid oxide etch

Integrated-circuit manufacture method with aqueous hydrogen-fluoride and

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.

Contacts for semiconductor devices

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.

Antifuse structures

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.

Inverted field-effect device with polycrystalline silicon/germanium

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.

Capacitance measurement using an RLC circuit model

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.

Methods for fabricating anti-fuse structures

An integrated circuit having a semiconductor substrate and an anti-fuse structure formed on the semiconductor substrate. The anti-fuse structure includes a metal-one layer and an anti-fuse layer disposed above the metal-one layer. The anti-fuse layer has a first resistance value when the anti-fuse structure is unprogrammed and a second resistance value lower than the first resistance value when the anti-fuse structure is programmed. There is further provided an etch stop layer disposed above the anti-fuse layer, and an inter-metal oxide layer disposed above the etch stop layer with the inter-metal oxide layer has a via formed therein. Additionally, there is further provided a metal-two layer disposed above the inter-metal oxide layer. In this structure, a portion of the metal-two layer is in electrical contact with the anti-fuse layer through the via in the inter-metal oxide layer.

Methods and apparatus for fabricationg anti-fuse devices

Method of making antifuse structures using implantation of both neutral

The use of a test chip having a wide channel MOSFETs of different channel widths and effective gate lengths allows for an experimental determination of the fringe capacitance per unit width. The use of channel widths greater than 100 microns increases the accuracy of the measured capacitance values.

Test structure and method for determining metal-oxide-silicon field

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 region 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 SRAM cells.

Field effect device with polycrystalline silicon channel

Disclosed is a method for programming an antifuse structure. The antifuse structure is programmed by applying an alternating current having alternating current pulses between a bottom and a top electrode to generate a conduction path through an antifuse material sandwiched between the electrodes. The conduction path is formed incrementally due to an electron flow produced as a result of each alternating current pulse thereby defining the conduction path at a substantially centered portion of the antifuse material.

Apparatus and method for programming antifuse structures

The punchthrough capacity of a p-type semiconductor device is significantly improved by nonuniformly doping the p-channel with n-type implants such as phosphorus. The n-type dopants are implanted at large angles to form pocket implants within the channel region. The dose of the implants, angle of the implants and the thermal cycle annealing of the implants will be optimized for maximum punchthrough capability without substantially detracting from the performance of the semiconductor device.

Angled lateral pocket implants on p-type semiconductor devices

A method for forming a connection between two levels in a semiconductor structure includes first forming a VIA (14) through an insulating layer (12) to an underlying structure (10). Sidewall spacers (22) and (24) are formed on the vertical walls of the VIA (14). The spacers (22) and (24) have tapered surfaces. A barrier layer (30) is then formed over the bottom surface of the VIA followed by CVD deposition of a conductive layer (32) of WSi.sub.2 to provide a conformal conductive layer. An aluminum layer (38) is then deposited by physical vapor deposition techniques with the descending portions of layer (32) providing a conductive connection between the aluminum layer (38) and the lower structure (10) in the VIA (14).

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Dallas, TX, United States of America

Yu-Pin Han