Advanced Micro Devices Corporation

Lattice Semiconductor Corporation

Vlsi Technology, Inc.

Chun Jiang

Sunil D Mehta

Hamid Partovi

Minh Van Ngo

Angela Tai Hui

Steven C Avanzino

Yowjuang William Liu

Wei Long

Stewart G Logie

Robert H Tu

David Donggang Wu

Zicheng Gary Ling

Yowjuang Bill Liu

Linda S Milor

Bill Yowjuang Liu

A zero power memory cell includes first and second NMOS transistors and a PMOS transistor, wherein the first NMOS transistor and first PMOS transistor each include a three-implant channel region, and wherein the second NMOS transistor further includes a two-implant channel region.

Zero power memory cell with reduced threshold voltage

A method for forming a uniformly planarized structured in a semiconductor wafer forms metal structures on a substrate layer with spaces between the structures. The top surfaces of the metal structures lie within a common plane. Dielectric material is deposited on the layer, the metal structures and in the spaces. The dielectric layer is first etched so that the dielectric material in the spaces is below the common plane. Additional dielectric material is then deposited on the layer, the metal structures and in the spaces. The dielectric layer is then subjected to a second etching. Further deposition and etching steps are performed until the top of the dielectric layer and the top surfaces of the metal structures have a common, substantially uniform planarization.

Method of forming uniformly planarized structure in a semiconductor wafer

A method for forming a three transistor zero power memory cell including a p-channel sense transistor, an n-channel write transistor, and an n-channel sense transistor including: implanting a p-type impurity into a p-type substrate in which a n-channel high voltage transistor will be formed; implanting an n-type impurity into an n-type well in a p-type substrate in which a p-channel high voltage transistor will be formed; forming a mask to allow implants to occur to p-channel devices; performing a series of n-type dopant implants into the substrate where the p-channel transistors will be formed; growing a high voltage gate oxide; forming a mask to allow implants to occur to n-channel devices, said mask blocking implants to said n-channel sense transistor; and performing a series of p-type implants into the substrate where the n-channel devices will be formed. In addition, a memory cell which may include a first NMOS transistor having a source, drain and gate, and a first PMOS transistor is disclosed. The memory cell includes a first and second NMOS transistors, and a PMOS transistor, wherein the first NMOS transistor and first PMOS transistor each include a three implant channel region, and wherein the second NMOS transistor further includes a two implant channel region.

Zero power memory cell with improved data retention

An EEPROM device having improved data retention and process for fabricating the device includes a two-step deposition process for the fabrication of an ILD layer overlying the high voltage elements of an EEPROM memory cell. The ILD layer is fabricated by first depositing an insulating layer on a high voltage device layer and thermally treating insulating layer. A second insulating layer is then deposited to overlie the first insulating layer. An EEPROM device in accordance with the invention includes a floating-gate transistor having a specified threshold voltage. A thermally-treated, boron-doped oxide layer overlies the floating-gate transistor and a second oxide layer overlies the thermally-treated, boron-doped oxide layer. The memory device exhibits data retention characteristics, such that upon subjecting the device to a baked temperature of at least about 250&deg; C. for at least about 360 hours, the threshold voltage of the floating-gate transistor shifts by no more than about 100 mV.

EEPROM device having improved data retention and process for fabricating the device

An improved method for fabricating a tunnel oxide window for use in an EEPROM memory cell is provided so as to produce better programming endurance. P-type lightly-doped drain regions are located at the polysilicon edges of the tunnel window. During the programming operation, the P-type lightly-doped drain regions are in contacting with the polysilicon edges. As a result, there is reduced or suppressed the tunneling current to the program junction region so as to improve the efficiency of programming.

EEPROM with a neutralized doping at tunnel window edge

The capacitance between the gate of a transistor and local interconnect is reduced employing SiC as an etch stop layer. Embodiments include depositing a SiC etch stop layer having a thickness of about 500-1000 &angst; and a dielectric constant of less than about 3.2, thereby providing a composite dielectric constant between the gate and local interconnect of between about 3.7 to about 4.7. The SiC etch stop layer can be deposited by PECVD or HDP techniques.

Interconnect methodology employing a low dielectric constant etch stop layer

An improved method for fabricating a tunnel oxide window for use in an EEPROM memory cell is provided so as to produce better programming endurance. A P&plus; implant is provided at the tunnel window edge. During the programming operation, the P&plus; contacted inversion layer is used instead of the program junction. As a result, there is eliminated the voltage drop in the program junction region so as to improve the efficiency of programming.

EEPROM tunnel window for program injection via P&plus; contacted inversion

Eeprom tunnel window for program injection via P&plus; contacted inversion

Air gap insulation regions are formed selectively within high parasitic capacitance regions in which conductive lines are closely proximate and generates an intolerable amount of parasitic capacitance. The selective formation of air gap insulation regions improves circuit performance by reducing the parasitic capacitance and device reliability by reducing the stress fracture problem of conventional air gap insulation schemes.

Selective air gap insulation

The invention provides a method and apparatus for calculating gate length and source/drain gate overlap, by measuring gate capacitance. The invention uses previously known fringe capacitance C.sub.fr and unit capacitance C.sub.OX. The invention measures gate capacitance C.sub.g, when the gate is accumulatively biased, and solves for overlap capacitance C.sub.OV using the equation C.sub.OV =(C.sub.g -2C.sub.fr)/2 or C.sub.OV =(C.sub.gg -C.sub.gb -2C.sub.fr)/2. The invention then measures the gate capacitance C.sub.g when the gate to source/drain voltage is set to inversion bias and a zero voltage is applied between the source/drain and the substrate, and solves for the channel capacitance C.sub.ch using the equation C.sub.ch =C.sub.g -2C.sub.fr -2C.sub.OV. The invention calculates the channel capacitance C.sub.ch where C.sub.ch =C.sub.g -2C.sub.fr -2C.sub.OV and then calculates gate length where gate length L.sub.g =(2C.sub.OV +C.sub.ch)/C.sub.OX and the effective gate length L.sub.eff =C.sub.ch /C.sub.OX. The invention further calculates source/drain gate overlap L.sub.OV, by setting L.sub.OV =C.sub.OV /C.sub.OX.

Method for measuring gate length and drain/source gate overlap

The capacitance between a gate electrode of a transistor and local interconnect is reduced by employing SiC sidewall spacers on the side surfaces of the gate electrode when forming the source/drain regions with shallow extensions. Embodiments include forming SiC sidewall spacers at a width of about 500 .ANG. to about 800 .ANG. having a dielectric constant of less than about 3.2, depositing a silicon oxide inter-dielectric layer, and forming the local interconnect through the inter-dielectric layer. The resulting composite dielectric constant between the gate electrode and local interconnect is about 4.2 to about 4.7.

Method to reduce gate-to-local interconnect capacitance using a low

When simulating a circuit's behavior, a transistor can be modeled to account for gate resistance induced propagation delay. In one embodiment, the model includes a transistor with a resistor connected to the gate of the transistor. The resistor has a resistance equal to one third of the gate resistance.

Model for taking into account gate resistance induced propagation delay

A system for simplifying and expediting estimation of the gate RC delay and/or the determination of transistor widths for a given gate RC delay in a CMOS inverter circuit. The system determines gate RC delay as a function of transistor width. Alternatively, appropriate transistor widths may be determined based on a desired optimum gate RC delay. An analytical expression is established to predict RC induced gate propagation delay as a function of readily available technical parameters in the early stage of design. The analytical expression has been found to describe gate RC delay in CMOS inverter circuits incorporating 0.25 micron (or even smaller) manufacturing technology.

System for designing and manufacturing CMOS inverters by estimating gate

A method and apparatus that uses gate-to-substrate capacitance with varying amounts of source/drain junction bias to measure channel lateral doping profile by applying a series of different voltages between the source/drain and the substrate. The gate capacitance is measured for the different voltages. The capacitance is used to calculate the depletion width. From the depletion width, channel doping is calculated. Using this method direct evidence of a localized Boron pile up at source/drain edge is shown.

C-V method to extract lateral channel doping profiles of MOSFETs

A system and method for providing a plurality of interconnects for a microcircuit is disclosed. The microcircuit has a plurality of functional components. The method and system include determining the placement of each of the plurality of functional components and determining a width of each of the plurality of interconnects. The determination of the width is based on a capacitance between each interconnect and a portion of the plurality of interconnects.

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San Jose, CA, United States of America

Chun Jiang