Motorola Corporation

Yee-Chaung See

Patrice M Parris

John R Alvis

Thomas C Mele

Syd R Wilson

Wayne R Burger

Lewis E Terry

Thomas E Zirkle

Juan Buxo

Craig A Cavins

Irenee M Pages

Han-Bin K Liang

Charles F Hart

Kuang-Yeh Chang

Eric Scott Carman

Quang Xuan Nguyen

Thierry Michel Sicard

A single level gate NVM device (20) includes a floating gate FET (11) and a capacitor (12) fabricated in two P-wells (27, 28) formed in an N-epitaxial layer (22) on a P-substrate (21). P+ sinkers (29, 31) and N-type buried layers (25, 26) provide isolation between the two P-wells (27, 28). The NVM device (20) is programmed or erased by biasing the FET (11) and the capacitor (12) to move charge carriers onto or away from a conductive layer (36) which serves as a floating gate (14) of the FET (11). Data is read from the NVM device (20) by sensing a current flowing in the FET (11) while applying a reading voltage to the capacitor (12).

Single level gate nonvolatile memory device and method for accessing the

A single level gate NVM device (10) includes p-channel and n-channel floating gate FETs (12, 14), an erasing capacitor (26), and a programming capacitor (28). The NVM device (10) is programmed by applying a programming voltage to the programming capacitor (28) and applying a ground voltage to the sources of the FETs (12, 14). The NVM device (10) is erased by applying an erasing voltage to the erasing capacitor (26) and applying ground voltage to the sources of the FETs (12, 14) and to the programming capacitor (28). Data is read from the NVM device (10) by sensing a voltage level at the drains of the FETs (12, 14) while applying a logic high voltage to the source of the p-channel FET (12), a logic low voltage to the source of the n-channel FET (14), and a reading voltage to the programming capacitor (28).

A nonvolatile memory cell (10) includes a single n-channel insulated gate FET (11) having a single floating gate (12). The FET (11) operates asymmetrically in a sense that the capacitance of a parasitic gate-source capacitor (24) is smaller than the capacitance of a parasitic gate-drain capacitor (26). The asymmetric condition is achievable either by fabricating the FET (11) as an asymmetric structure (30, 60) or by adjusting the capacitance of the parasitic capacitors (24, 26) through terminal biasing when the FET (11) is a short channel device. The potential of the floating gate (12) is controlled by biasing the source (14), drain (16), and substrate (18) of the FET (11). The cell (10) is programmed by moving charge onto the floating gate (12) via hot carrier injection, erased by moving charge from the floating gate (12) via tunneling, and read by sensing the conductive state of the FET (11).

Single gate nonvolatile memory cell and method for accessing the same

A method of fabricating an integrated circuit (272) having memory, logic, high voltage, and high current functionality uses a modular implant process step (104) to form a drain extension region (204), a source extension region (205), and a base extension region (206) in a substrate (200). The dopants from the modular implant process step (104) are later diffused into the substrate (200) during a LOCOS process step (105). A modular gate oxide formation step (111) produces three different thicknesses of gate oxides (309, 311, 312) which provide ultra high voltage, high voltage, and low voltage functionality for the integrated circuit (272).

Method of fabricating an EPROM with high voltage transistors

A non-volatile memory cell (10) is provided employing two transistors (11, 12) connected in series. A floating gate structure (13), formed with a single polysilicon deposition, is shared by each transistor (11, 12) to store the logic condition of the memory cell (10). To program and erase the memory cell (10), a voltage potential is placed on the floating gate (13) which modulates the transistors (11, 12) so only one is conducting during read operations. The gate capacitance of the transistors (11, 12) is used to direct the movement of electrons on or off the floating gate structure (13) to place or remove the stored voltage potential. The two transistor memory cell (10) couples one of two voltage potentials as the output voltage so no sense amp or buffer circuitry is required. The memory cell (10) can be constructed using traditional CMOS processing methods since no additional process steps or device elements are required.

Non-volatile memory cell having a single polysilicon gate

A lateral bipolar transistor (10) includes a retrograde doping profile (21) that is formed within a substrate (11) to form the transistor's (10) collector region (14). A base region (16) that includes an inactive base area and an active base area (17) is formed in the collector region (14). An emitter (18) is formed within the active base area (17) wherein current (22) flows through the emitter (18) through the active base area (17) and through the collector region (14). The base region, the emitter, and a collector contact region are all formed by driving dopants from an overlying polysilicon layer.

Lateral bipolar transistor

A BiCMOS device and process are disclosed wherein the transistors components are fabricated on an SOI substrate. A SIMOX process is used to form a buried oxide layer in a single crystal silicon substrate followed by an epitaxial deposition to form a silicon body of varying thickness overlying the buried oxide layer. MOS transistors are then formed in a thin portion of the epitaxial layer and a vertical bipolar transistor is formed in the thick portion of the epitaxial layer. In accordance with one embodiment of the invention, a single crystal semiconductor substrate is provided having a principal surface and a buried oxide layer underlying the first surface. A lightly doped epitaxial layer of a first conductivity type having a thin MOS region and a thick bipolar region overlies the principal surface. A first and second isolation regions extending from the first surface to the buried oxide layer separate and electrically insulate the bipolar region from the MOS region. An NMOS and a PMOS transistor are formed in the thin MOS region and are separated by a third isolation region extending from the first surface to the buried oxide layer. A vertical bipolar is formed in the electrically insulated bipolar region of the epitaxial layer.

Process for making BiCMOS device having an SOI substrate

BiCMOS device having an SOI substrate and process for making the same

A method of fabricating a trench structure includes providing a substrate having a first layer disposed on a surface thereof and a second layer disposed on the first layer. A trench is formed through the first and second layers and into the substrate. A dielectric liner is formed on the sidewalls of the trench which is then filled with a trench fill material. Portions of the trench liner disposed above the trench fill material are removed and a conformal layer is then formed on the trench structure. The conformal layer and a portion of the trench fill material are then oxidized.

Method of fabricating a trench structure

Implementing modified souce/drain implants in a non-volatile memory process while leaving the source/drain regions in the memory cells of the device unmodified and adding no critical mask steps. Methods for implementing both low dose drain and graded source/drain modifications in a double poly non-volatile memory process include the possibility of leaving the spacers used to modify the peripheral source/drain regions in place in the array portion of the device. Alternate methods include the possibility of removing the spacers in the array portion without the addition of critical mask steps and of keeping the spacers out of the array portion entirely.

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Phoenix, AZ, United States of America

Yee-Chaung See