Harris Corporation

Other

Lawrence G Pearce

Donald Frank Hemmenway

Dyer A Matlock

Richard L Lichtel, Jr

John T Gasner

Patrick Anthony Begley

Jeanne Marie McNamara

John J Hackenberg

Choong S Rhee

Kenneth K O

Dryer A Matlock

Monolithic class D amplifier

Trenches 72 are formed in substrate 17 late in the fabrication process. In order to avoid trench sidewall stresses that cause defects in the substrate monocrystalline lattice, the trenches are filled after a final thick thermal oxide layer, such as a LOCOS layer 25, is grown. The trenches 72 are also filled after a final deep diffusion, i.e. a diffusion in excess of one micron.

Late process method and apparatus for trench isolation

Late process method for trench isolation

A two masking level process for a dual buried region epitaxial architecture forms a first masking layer on a surface of a P type substrate. The first masking layer exposes first and second surface portions of the substrate for N+ and P+ buried regions. N type impurities are introduced into the substrate through the first masking layer, so as to form N+ doped regions. A second masking layer is then selectively formed on the first masking layer, such that the second masking layer masks the first aperture, but exposes a second portion of the first masking layer that both includes and surrounds the second aperture. Boron impurities are then introduced through the exposed second aperture of the first masking layer, to a P+ doping concentration. That portion of the first masking layer surrounding the second aperture is removed, and boron impurities are then introduced into exposed second and third surface portions of the substrate, thereby forming a third buried region of the second conductivity type that is adjacent to the second doped region. The composite mask is removed from the substrate, and an N type layer is grown. Due to differences in diffusion coefficients, the P dopant (boron) in the second and third buried regions outruns the N dopant in the second buried region, resulting in the formation of an N+ buried region that is encapsulated in a P+ buried region. The P+ buried region is, in turn, laterally surrounded by a P-type buried region, so as to provide the desired compensation of N ions that are autodoped from the first N+ buried region in the epitaxial layer.

Method of making high voltage, junction isolation semiconductor device

A QVDMOS array 10 has QVDMOS devices with a silicide contact 42 to source 35 and body tie 36. The body tie 36 is enclosed by the source at the surface and extends beneath but not beyond the annular source 35. The QVDMOS is formed during a number of process steps that simultaneously form regions in NMOS, PMOS and bipolar devices.

High efficiency quasi-vertical DMOS in CMOS or BICMOS process

A power MOS switch (40) is an array of MOS devices that includes alternating drain columns and source columns. Each drain column includes a plurality of separate drain regions (300) that are closely spaced one from another, and each source column includes a continuous narrow elongated source distribution region (302) that extends the length of the column. A plurality of narrow source distribution branch regions (302) are connected to the elongated region and extend transversely from the elongated region at least partially between each separate drain region in each drain column adjacent to the source column. A gate region (303) separates the drain regions in each column from the adjacent source distribution regions.

High efficiency power MOS switch

An isolated pilot transistor 100 for a QVDMOS device 10 has a gate and drain region in symmetry with the sources 20 of device 10 and an additional resistance 116 in the drain 118 to compensate for current spreading between the source 120 and the buried layer resistor 132.

Pilot transistor for quasi-vertical DMOS device

An integrated circuit 10 has a programmable Zener diode with diffusion regions 18 and 16 and metal contacts 34 and 32. A barrier metal 30 is disposed between one contact 32 and the substrate 12; another contact region 18 has no barrier metal on its surface. A polysilicon layer 22 is self-aligned with surface regions 18 and diffusion region 18. A silicide layer 128 may be used on the polysilicon layer 22 and on surface region 18.

Programmable element in barrier metal device

A method for electrically isolating semiconductor devices in an integrated circuit structure with high field threshold, low defect level regions. The semiconductor structure includes a device layer predominantly comprising lattice silicon with a surface suitable for device formation. Multiple device regions are defined and field regions are defined for electrically isolating the device regions from one another. Dopant species are implanted to create a channel stop adjacent two of the device regions. The implant is of sufficient energy and concentration to impart within the device layer nucleation sites of the type known to result in stacking faults during oxide growth conditions. A thickness of thermally grown silicon dioxide is formed in the field regions by first thermally processing the integrated circuit structure to remove nucleation sites from the device layer and form a minor portion of the field oxide thickness. Subsequently a major portion of the oxide thickness is formed under relatively fast growth conditions.

Local oxidation process for high field threshold applications

High voltage, junction isolation semiconductor device having dual

The problem of unwanted residual polysilicon stringers along the sidewalls of a field oxide layer employed in direct moat wafer processing is avoided by a processing scheme in which the sidewalls of the aperture in the field oxide layer are initially tapered prior to formation of the polysilicon layer to be used for the gate electrode(s). Because of the graduated thickness of the sidewalls of the field oxide layer, the thickness of the polysilicon layer formed thereon is substantially uniform over the entirety of the substrate. As a result, during subsequent masking of the polysilicon layer to define the gate electrode(s), all unmasked portions of the polysilicon are completely etched, leaving no residual material (e.g. stringers) that could be a source of device contamination. After the polysilicon gate has been delineated, the sloped sidewalls of the field oxide are removed (by anisotropic etching), so that the sidewalls of the apertures or windows of the field oxide layer will be perpendicular to the planar surface of the substrate, thus facilitating proper formation of dielectric (oxide) spacers therealong, which thereby provide separation between contact materials and the junction created by shallow ion implantation of dopants through the field oxide aperture.

Technique for elimination of polysilicon stringers in direct moat field

The separation constraint between the respective junctions formed between the drain regions of the complementary transistors and the semiconductor material in which they are formed is obviated by a structure which permits the respective drain regions of the opposite conductivity type transistors to have a reduced (effecting to zero) mutual separation and, at the same time, prevent the depletion regions fomed between the junctions defined by these source regions and the semiconductor material in which they are formed from spreading into contact with one another and thereby shorting the transistors together. This objective is achieved by a structure in which the source regions of the respective P and N channel transistors are formed so as to directly abut against one another and to be contiguous with a layer of buried dielectric isolation therebeneath. The buried dielectric layer extends from the bottom portions of the drain regions to a prescribed depth in each of the P-well region and the N-type substrate, so as to effectively provide a barrier between depletion region associated with the junction defined by the P well and N substrate the depletion regions formed between the N+ drain region and the P-well and the P+ drain region and the N-type substrate.

CMOS device having reduced spacing between N and P channel

A direct moat wafer processing for maximizing the functional continuity of a field oxide layer employs a processing sequence through which respective differently sized apertures are successively formed in the oxide layer. A first of these apertures prescribes the size of the polysilicon gate, while a second aperture is formed around the completed gate structure and prescribes the geometry of source/drain regions to be introduced into exposed surface areas of the substrate on either side of the gate. The sidewalls of the first and subsequently formed, second aperture are effectively perpendicular to the substrate surface, thereby maintaining the functional continuity of the field oxide layer across the entirety thereof. Thereafter, a separate gate interconnect layer is selectively formed atop the field oxide layer to provide a conductive path to the gate.

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Palm Bay, FL, United States of America

Lawrence G Pearce