National Semiconductor Corporation

Douglas Brisbin

Andy Strachan

Andrew Derek Strachan

Prasad Chaparala

Sergei Drizlikh

Heather McCulloh

Denis Finbarr O'Connell

Peter J Hopper

Vladislav Vashchenko

Yuri Mirgorodski

Alexander H Owens

David Tsuei

An insulating material interposed between two conductive materials can experience plasma process induced damage (PPID) when a plasma process is used to deposit a dielectric onto one of the conductive materials. This PPID can be reduced by reducing electric charge accumulation on the one conductive material during the plasma process dielectric deposition.

Method and apparatus for reducing plasma process induced damage in integrated circuits

A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant. Other aspects of the invention are methods for designing a PMOS device including by determining relative locations of the gate and at least one of the drain junction breakdown and maximum impact ionization points to reduce drain breakdown voltage walk-in, and methods for manufacturing integrated circuits including any embodiment of the PMOS device of the invention.

Method for designing and manufacturing a PMOS device with drain junction breakdown point located for reduced drain breakdown voltage walk-in

A number of modified lateral DMOS (LDMOS) transistor arrays are formed and tested to determine if a measured value, such as a series on-resistance, substrate current, breakdown voltage, and reliability, satisfies process alignment requirements. The modified LDMOS transistor arrays are similar to standard LDMOS transistor arrays such that the results of the modified LDMOS transistor arrays can be used to predict the results of the standard LDMOS transistor arrays.

Method of monitoring process misalignment to reduce asymmetric device operation and improve the electrical and hot carrier performance of LDMOS transistor arrays

A MOS transistor is formed with a dual-layer silicon oxynitride (SiON) etch stop film that protects the transistor from plasma induced damage (PID) and hot carrier degradation, thereby improving the reliability of the transistors. The first SiON layer is formed with SiHat a first flow rate, and the second SiON layer is formed with SiHat a second higher flow rate.

MOS transistor and method of forming the MOS transistor with a SiON etch stop layer that protects the transistor from PID and hot carrier degradation

The drain breakdown voltage walk-in of a dual-source, dual-gate PMOS transistor is significantly reduced by utilizing source regions which have a width that is equal to or less than a width of the drain region. By utilizing source regions with widths that are equal to or less than the width of the drain region, the current density in the drain region is significantly reduced which reduces the number of hot charge carriers that are trapped at the silicon-to-silicon dioxide interface which, turn in, reduces the drain breakdown voltage walk-in rate.

Multi-source, multi-gate MOS transistor with a drain region that is wider than the source regions

PMOS device with drain junction breakdown point located for reduced drain breakdown voltage walk-in and method for designing and manufacturing such device

An LDMOS structure which provides for reduced hot carrier effects. The reduction in hot carrier effects is achieved by increasing the size of the drain region of the LDMOS relative to the size of the source region. The larger size of the drain region reduces the concentration of electrons entering the drain region. This reduction in the concentration of electrons reduces the number of impact ionizations, which in turn reduces the hot carrier effects. The overall performance of the LDMOS is improved by reducing the hot carrier effects.

LDMOS transistor structure for improving hot carrier reliability

A method of programming a PMOS stacked gate memory cell is provided that utilizes the correlation between injection current and substrate current during the programming cycle to provide a feedback correction to the control gate of the memory cell to compensate for the negative potential shift on the floating gate as a result of its charging time.

Efficient method of PMOS stacked-gate memory cell programming utilizing feedback control of substrate current

In a LDMOS transistor or matrix of transistors, hot carrier degradation effects are reduced by providing a ring drain and providing the ring drain with an overvoltage bias relative to the internal drain(s) of the LDMOS transistors.

Method and device for improving hot carrier reliability of an LDMOS transistor using drain ring over-drive bias

The safe operating area of a high-voltage MOSFET, such as a lateral double-diffused MOS (LDMOS) transistor, is increased by using transistor cells with an X-shaped body contact region and four smaller source regions that adjoin the body contact region. The X-shaped body contact region lowers the parasitic base resistance of the transistor, thereby increasing the safe operating area of the transistor.

Power MOSFET cell with a crossed bar shaped body contact area

An LDMOS array includes an array of alternating source regions and drain regions formed in a semiconductor substrate to define a checkerboard pattern of source and drain regions. A source contact is formed in electrical contact with each of the source regions in the array to connect the source regions in parallel. A drain contact is formed in electrical contact with each of the drain regions in the array to connect the drain regions in parallel. A drain ring is formed around the periphery of the checkerboard pattern and in electrical contact with the drain contact, providing redistribution of the current flow within the LDMOS array and thereby allowing safer hot carrier operation at higher biases than with the conventional layout.

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San Jose, CA, United States of America

Douglas Brisbin