Vantis Corporation

Lattice Semiconductor Corporation

Motorola Corporation

Steven J Fong

Sunil D Mehta

Stewart G Logie

Xiao-yu Li

Robert J Mattox

Xiao-Yu Li

John Schadt

Brad Sharpe-Geisler

Luan Phoc Chau

Thomas R Gustafson

Shawn Murray

Two (or more) different, but complementary, families of integrated circuits having the same layout are developed simultaneously where the different families are achieved by changing one or more design parameters of transistors used to implement the integrated circuits. For example, a low-power (but low-speed) family of one or more ICs (e.g., for handheld applications) can be achieved by designing at least some transistors with relatively high threshold-voltage (Vt) levels, while a different, but complementary, high-speed (but high-power) family of one or more ICs (e.g., for server applications) can be achieved by designing corresponding transistors with relatively low Vt levels. In this way, the two families can share in common all but a very few masks used to fabricate the ICs of the different families.

Simultaneous development of complementary IC families

In one embodiment, an integrated circuit includes a substrate having high voltage transistor regions and low voltage transistor regions. The substrate includes a first trench between and adjacent to the high voltage transistor regions, a second trench between and adjacent to the low voltage transistor regions, and a third trench between the first and second trenches and between and adjacent to a high voltage transistor region and a low voltage transistor region. A thicker silicon dioxide layer lines the first trench and a first portion of the third trench adjacent to a high voltage transistor region. A thinner silicon dioxide layer lines the second trench and a second portion of the third trench adjacent to a low voltage transistor region. A silicon nitride layer is present on the thinner silicon dioxide layer and lines the second trench and the second portion of the third trench but is not present on the thicker silicon dioxide layer and does not line the first trench and the first portion of the third trench.

Shallow trench isolation (STI) with trench liner of increased thickness

A method of manufacturing an integrated circuit includes etching a substrate to create simultaneously a first trench between high voltage transistor regions of the substrate and a second trench between low voltage regions of the substrate. The substrate is then oxidized to form a silicon dioxide layer lining the first and second trenches, the layer having a first thickness. A silicon nitride layer is deposited on the silicon dioxide layer in the first and second trenches. The silicon nitride layer is then etched from the first trench but not from the second trench, thereby exposing the silicon layer in the first trench but not the second trench. The exposed silicon dioxide layer in the first trench is oxidized to increase the thickness of the silicon dioxide layer to a second thickness greater than the first thickness of the unexposed silicon dioxide layer in the second trench. The first and second trenches are then filled with a dielectric material.

Complementary avalanche injection EEPROM cell

An EEPROM cell is described that is programmed and erased by electron tunneling across an entire portion of separate transistor channels. The EEPROM cell has three transistors formed in a semiconductor substrate. The three transistors are a tunneling transistor (PMOS), a sense transistor (NMOS) and a read transistor (NMOS). Electron tunneling occurs to program the EEPROM cell through a sense tunnel oxide layer having a thickness to allow the electron tunneling across an entire portion of a sense channel upon incurrence of a sufficient voltage potential between a floating gate and the tunnel channel. Electron tunneling also occurs to erase the EEPROM cell through a tunnel oxide layer having a thickness to allow electron tunneling across an entire portion of a tunneling channel upon incurrence of a sufficient voltage potential between the floating gate and the tunneling channel.

EEPROM cell with tunneling across entire separated channels

A non-volatile memory cell, comprising a semiconductor substrate having a first conductivity type. A control region is formed of said first conductivity type in the substrate and a control region oxide formed over the control region. The cell includes a program element having a first active region of a second conductivity type formed in said substrate, a doped or implanted region adjacent to said first active region, and a gate oxide overlying at least the channel region. An active region oxide covers a portion of the first active region. A floating gate is formed over said semiconductor substrate on said active region oxide and said control region oxide.

Avalanche injection EEPROM memory cell with P-type control gate

An EEPROM cell is described that is programmed and erased by electron tunneling at separate regions, an edge of a tunneling drain and a sense transistor channel. The EEPROM cell has three transistors formed in a semiconductor substrate. The three transistors are a tunneling transistor (NMOS), a sense transistor (NMOS) and a read transistor (NMOS). Electron tunneling occurs to program the EEPROM cell through a sense tunnel oxide layer by electron tunneling across an entire portion of a sense channel upon incurrence of a sufficient voltage potential between a floating gate and the sense channel. Electron tunneling also occurs to erase the EEPROM cell through a tunnel oxide layer be electron tunneling at an edge of a tunneling drain upon incurrence of a sufficient voltage potential between the floating gate and the tunneling drain.

EEPROM cell with tunneling at separate edge and channel regions

A two transistor EEPROM cell is described that is erased by electron tunneling across an entire portion of a tunneling channel and programmed by electron tunneling at an edge of a tunneling drain.

Two transistor EEPROM cell

A non-volatile memory cell structure which includes a floating gate, a reverse breakdown element and a read transistor. The reverse breakdown element is at least partially formed in a first region of a first conductivity type in a semiconductor substrate, and underlies a portion of the floating gate; and the read transistor is at least partially formed in the first region and connected to the reverse breakdown element. In a further embodiment a control gate is capacitively coupled to the floating gate and is formed in a second region of the substrate, outside the well region.

PMOS avalanche programmed floating gate memory cell structure

A method of creating a reverse breakdown condition in an array of memory cells arranged in columns and rows in the array, and an array structure are provided. The method comprises the steps of applying a first voltage on a first column connection coupling a first column of said cells, and a second voltage on a second column connection coupling a second column of said cells; and applying a third voltage on a first row connection coupling a first row of said cells, and applying said second voltage on a second row connection coupling a second row of said cells. In this aspect, the difference between the first voltage and the third voltage creates said reverse breakdown condition in at least one cell occupying said first column and first row. In a further aspect, each cell includes a floating gate and the method of the invention includes the step of programming one of said cells by coupling a control voltage to each floating gate. The structure includes a substrate having formed therein at least an Nth or Mth row-wise oriented well, each well isolated from adjacent ones of said wells. Also provided are at least an Nth and Mth word bit line formed by an Nth and Mth impurity regions in said substrate and at least an Nth and Mth array control gate lines. A plurality of memory cells, each cell formed in at least said Nth or Mth row-wise well, is further provided. Each cell comprises a drain, a floating gate, a drain connection one of said Nth or Mth word bit line (WBL), and a substrate well connection to one of said Nth or Mth wells, and a control gate connection to one of said Nth or Mth array control gate lines(ACG).

Floating gate memory apparatus and method for selected programming

A zero-power non-volatile memory cell includes a control element, an avalanche injection element, and a CMOS inverter. A floating-gate electrode is capacitively coupled to the control element, the avalanche injection element, and to the CMOS inverter. The avalanche injection element is arranged, so as to transfer electrical charge onto the floating-gate electrode. The presence of stored data within the memory cell is indicated by reading a supply voltage V.sub.DD at an output terminal of the inverter. Accordingly, data can be read from the non-volatile memory cell without applying electrical power to the cell.

Zero-power CMOS non-volatile memory cell having an avalanche injection

A structure and method for forming an isolation wall in an etched trench are described. The trench walls are covered by a thin silicon oxide layer and the trench conformally filled with an oxy-nitride mixture having a particular range of composition so as to produce a neutral to slight tensile stress in the oxy-nitride relative to silicon. The structure is very simple to fabricate and creates fewer defects in the silicon substrate than prior art techniques. Buried voids in the filled trench are eliminated.

Growing community of inventors

Santa Clara, CA, United States of America

Steven J Fong