Various embodiments for improved power devices as well as their methods of manufacture, packaging and circuitry incorporating the same for use in a wide variety of power electronic applications are disclosed. One aspect of the invention combines a number of charge balancing techniques and other techniques for reducing parasitic capacitance to arrive at different embodiments for power devices with improved voltage performance, higher switching speed, and lower on-resistance. Another aspect of the invention provides improved termination structures for low, medium and high voltage devices. Improved methods of fabrication for power devices are provided according to other aspects of the invention. Improvements to specific processing steps, such as formation of trenches, formation of dielectric layers inside trenches, formation of mesa structures and processes for reducing substrate thickness, among others, are presented. According to another aspect of the invention, charge balanced power devices incorporate temperature and current sensing elements such as diodes on the same die. Other aspects of the invention improve equivalent series resistance (ESR) for power devices, incorporate additional circuitry on the same chip as the power device and provide improvements to the packaging of charge balanced power devices.

Power semiconductor devices and methods of manufacture

The potential impact of high-/spl kappa/ gate dielectrics on device short-channel performance is studied over a wide range of dielectric permittivities using a two-dimensional (2-D) simulator implemented with quantum mechanical models. It is found that the short-channel performance degradation is caused by the fringing fields from the gate to the source/drain regions. These fringing fields in the source/drain regions further induce electric fields from the source/drain to channel which weakens the gate control. The gate dielectric thickness-to-length aspect ratio is a proper parameter to quantify the percentage of the fringing field and thus the short channel performance degradation. In addition, the gate stack architecture plays an important role in the determination of the device short-channel performance degradation. Using double-layer gate stack structures and low-/spl kappa/ dielectric as spacer materials can well confine the electric fields within the channel thereby minimizing short-channel performance degradation. The introduction of a metal gate not only eliminates the poly gate depletion effect, but also improves short-channel performance. Several approaches have been proposed to adjust the proper threshold voltage when midgap materials or metal gates are used.

The impact of high-/spl kappa/ gate dielectrics and metal gate electrodes on sub-100 nm MOSFETs

DRAM cell arrays having a cell area of about 4F 2 comprise an array of vertical transistors with buried bit lines and vertical double gate electrodes. The buried bit lines comprise a silicide material and are provided below a surface of the substrate. The word lines are optionally formed of a silicide material and form the gate electrode of the vertical transistors. The vertical transistor may comprise sequentially formed doped polysilicon layers or doped epitaxial layers. At least one of the buried bit lines is orthogonal to at least one of the vertical gate electrodes of the vertical transistors.

DRAM layout with vertical FETs and method of formation

An integrally packaged integrated circuit device including an integrated circuit die including a crystalline substrate having first and second generally planar surfaces and edge surfaces and an active surface formed on the first generally planar surface, at least one chip scale packaging layer formed over the active surface and at least one electrical contact formed over the at least one chip scale packaging layer, the at least one electrical contact being connected to circuitry on the active surface by at least one pad formed on the first generally planar surface.

Methods and apparatus for packaging integrated circuit devices

A packaged semiconductor chip includes features such as a chip carrier having a large thermal conductor which can be solder-bonded to a circuit board so as to provide enhanced thermal conductivity to the circuit board and electromagnetic shielding and a conductive enclosure which partially or completely surrounds the packaged chip to provide additional heat dissipation and shielding. The packaged unit may include both an active semiconductor chip and a passive element, desirably in the form of a chip, which includes resistors and capacitors. Inductors may be provided in whole or in part on the chip carrier. A module includes two circuits and an enclosure with a medial wall between the circuits to provide electromagnetic shielding between the circuits.

High-frequency chip packages

A method for producing field oxide in a silicon substrate by forming a thin oxide layer over the surface of the substrate, forming a thin nitride layer over the thin oxide layer, forming a thick oxide over the thin nitride layer, forming a thick nitride layer over the thick oxide layer; patterning all four of the layers to espose the surface of the substrate where the field oxide is to be formed; and growing the field oxide. Preferably, before the field oxide is grown, trenches are formed into the substrate so that the upper surfaces of the field oxide are substantially planar with the upper surfaces of the substrate. The thin oxide layer minimizes bird beak formation, and eases the removal of the oxide/nitride/oxide/nitride layers. The resultant structure is both planar and bird's beak-free, and is therefore well suited to producing VLSI components having dimensions less than 0.5 microns.

Method for producing recessed field oxide with improved sidewall characteristics

A MOSFET structure characterized by a lightly doped tip region located between the channel and drain, and a buried region located below the tip region and shifted laterally towards the drain. The buried region, which is doped to a level intermediate between that of the tip region and the drain, causes the channel current to deflect downwardly from the field oxide, through the lightly doped tip region, and into the buried region. The gradual electric field gradient produced by the structure and the deflection of the channel current away from the thin oxide greatly reduces the device's sensitivity to the hot electron effect. The method of the invention includes forming the lightly doped tip region, forming a first oxide spacer, forming the buried region, widening the oxide spacer, and finally forming the drain region.

Method for making an LDD MOSFET with a shifted buried layer and a blocking region

The time dependence of hot carrier degradation of n-channel MOSFETs and the methodology of accelerated stress have been investigated in detail. The time (T) dependence is found to be inconsistent with the simple expression of TN (N-0.25), but rather show a slow-down of the degradation rate. The slope of the degradation curve is also found to be dependent on the stress bias voltage. The projection of device lifetime by accelerated stress based on the TN law and the assumption of constant slope independent of stress bias is unreliable.

Self-Limiting Behavior of Hot Carrier Degradation and Its Implication on the Validity of Lifetime Extraction by Accelerated Stress

This invention pertains to a self-aligned trench-isolated emitter structure and the method for forming same. The emitter structure comprises a portion of a bipolar transistor which exhibits improved function due to the emitter structure. A single layer of conductive material forms both the emitter and base contacts in the transistor structure, which structure has particularly shallow emitter and base junctions (about 0.15 micrometer or less). The self-aligned emitter contact, isolated from the base contact by a dielectric filled trench, permits overall size reduction of the device, whereby junction area and accompanying leakage across junctions is reduced. In addition, when the structure of the bipolar transistor is such that the trench isolates the emitter area from both the base contact and the extrinsic base, it is possible to provide improved base conductivity without generating peripheral transistor effects. The bipoloar transistor can be either N-P-N type or P-N-P type depending on the materials of fabrication, although high speed devices are typically of the N-P-N type. The method includes forming a sidewall spacer (246), creating an etch-masking layer (250), removing the spacer, and etching an isolation trench at the location previously occupied by the spacer.

Process of making a bipolar transistor with a trench-isolated emitter

The apparatus and method for forming de-coupling capacitors on top of SOC VLSI chip. The introduced large amount of de-coupling capacitor is intended to solve the power delivery problem of highly integrated and powered VLSI chip, especially in the Silicon-On-Insulator (SOI) technology. This invention proposes a design scheme which could utilize virtually unused area to build efficient de-coupling capacitors without introducing additional manufacture cost. This design scheme is especially effective when the VLSI technology is scaled down further.

Paul Vande Voorde

Papers

Method for producing recessed field oxide with improved sidewall characteristics

Method for making an LDD MOSFET with a shifted buried layer and a blocking region

Self-Limiting Behavior of Hot Carrier Degradation and Its Implication on the Validity of Lifetime Extraction by Accelerated Stress

Process of making a bipolar transistor with a trench-isolated emitter

Method and apparatus for building up large scale on chip de-coupling capacitor on standard CMOS/SOI technology