D
Digital-to-Analog converter. A circuit that converts digital input signals to analog
output signals. D-to-A and A-to-D converters are a major product area for Intersil
Semiconductor and an important element of signal processing. See A/D converter and signal
processing.
The process by which events in the real world are translated to machine-readable
signals. The term usually refers to automated systems in which sensors are attached to
machinery.
An electrical circuit that changes direct current (DC) from one voltage level to
another. Frequently found in battery-operated systems.
The operating characteristics of an integrated circuit or discrete device that can be
measured with the device in a static condition. See parametric
tests.
Double Diffused Drain. See diffusion
and drain.
Defect Diagnostic Matrix. See defect.
A chemical or structural irregularity that degrades the crystal structure of silicon or
of the deposited materials that reside on its surface. Defects can be active mobile
impurities that impact the electrical device characteristics over time, or inactive
particulates that interfere with the photolithographic patterning. The most common defects
in semiconductor processing are those originating from people (oil, cosmetics, sneezing,
skin flakes, etc.)
A FET designed so that the channel is in the "on" state with no voltage
applied to the gate. See also channel, enhancement-mode FET, FET, gate and source.
The procedure in which materials are deposited onto a substrate. Usually refers to thin
conducting or insulating films used to form MOS gates, capacitors, thin-film resistors,
and the interconnect system for an IC.
Defense Electronic Supply Center. DESC, located in Dayton,
Ohio, is the agency responsible for procurement of electronic supplies for the U.S.
military. It certifies that semiconductor vendors are in compliance with military parts
specifics, such as MIL-M-38510. DESC also stocks piece parts for spares. Pronounced
"deh-see".
The operation in which a designer tailors the transistors exactly to their function in
the circuit. In the Intersil FASTRACK design system, very specific and accurate sizings of
transistors are made under the general categories of high speed, low noise, or high
current transistor types. See FASTRACK.
Design For Manufacturability utilizes statistical information on
manufacturing process characteristics to ensure that the circuit design falls within the
parameters of normal manufacturing variances for each process element. This allows the
designer to center the design for maximum performance and enhances yields, thereby
reducing cost.
Design For Reliability.
Design For testability is a design technique and methodology that
produces designs for which tests can be generated by known methods that will result in
reduced test generation cost, reduced testing cost, and high-quality product. This is
usually done at a cost of added overhead circuitry.
See dielectric isolation.
Dielectric Isolated Complementary Metal Oxide Semiconductor.
DICMOS ICs have proved to be an excellent solution for applications requiring very low
leakage current or over-voltage protection.
A single square or rectangular piece of semiconductor material into which a specific
electrical circuit has been fabricated. Plural: dice. Also called a chip.
An insulator. Localized regions of dielectric materials are used in semiconductor
devices, for example, to provide electrical isolation between dice, between metal
interconnect layers, and between the gate electrode and the channel.
A fabrication technique by which components in an integrated circuit are electrically
isolated from each other by an insulator (dielectric material).DI surrounds the sides and
bottom of each transistor with a layer of silicon dioxide (glass). DI has proven
particularly advantageous for fabricating high performance analog ICs. The conventional DI
fabrication process for bipolar ICs begins with a wafer of N-type silicon. The side of the
wafer that will eventually be the bottom is deeply etched (in V-shaped grooves) to form
the sidewall pattern, then silicon dioxide and polycrystalline silicon are grown to fill
the etched moats and to thicken the eventual DI substrate. The opposite side of the wafer
is polished until the insulating sidewalls appear at the wafer surface. Conventional
diffusion and metallization processes follow to complete the IC. Compare junction isolation and see bonded wafer.
A high temperature process in which chemical impurities (dopants) enter and move
through the crystalline lattice structure of a semiconductor material to change its
electrical characteristics. The process takes place in a diffusion furnace, usually at
temperatures between 850oC and 1150oC.
Represented in terms of discrete digits, each distinct from the next. A method of
representing and manipulating information by switching current on or off. Compare analog.
A class of integrated circuits that process digital information (expressed in binary
numbers). The processing operations are arithmetic (such as addition, subtraction,
multiplication, and division) or logical (in which the circuit senses certain patterns of
input binary information and indicates the presence or absence of those patterns by
appropriate output binary signals).
See DSP.
A two-terminal semiconductor (rectifying) device that exhibits a non-linear
current-voltage characteristic. The function of a diode is to allow current in one
direction and to block current in the opposite direction. The terminals of a diode are
called the anode and cathode. There are two kinds of semiconductor diodes: a P-N junction
diode, which forms an electrical barrier at the interface between N- and P-type
semiconductor layers, and a Schottky diode, whose barrier is formed between metal and
semiconductor regions. See rectifier.
Dual In-line Package. The most common type of integrated-circuit
package, which can be either plastic (DIP-Plastic) or ceramic (CERDIP). Circuit leads or
pins extend symmetrically outward and downward from opposite sides of the rectangular
package body. "DIP, side-brazed" is a dual in-line package with leads brazed
externally, on the sides of the package.
A class of electronic components, such as power MOSFETs, bipolar power transistors,
surgectors, MOVs, optoelectronic devices, rectifiers, power hybrid circuits, intelligent
power discretes, and transistors. Typically, these devices contain one active element,
such as a transistor or diode. However, hybrids, optoelectronic devices, and intelligent
discretes may contain more than one active element. In contrast, integrated circuits (ICs)
typically contain hundreds, thousands, or even millions of active elements in a single
die.
Double-Level Metal. An IC metal interconnect process that employs
two vertical levels of metal, separated by an insulating layer. DLM technology allows a
designer to use a smaller die size (for a given level of design functionality) than does
SLM. Compare SLM.
Deep Level Transient Spectroscopy.
Design Limited Yield. See yield.
An impurity from column V of the periodic table, which adds a mobile electron to the
conduction band of silicon, thereby making it more N-type. Commonly used donors are
arsenic and phosphorous. Compare acceptor.
The intentional introduction of a selected chemical impurity (dopant) into the crystal
structure of a semiconductor to modify its electrical properties. For example, adding
boron to silicon makes the material more P-type. Doping concentrations range from a few
parts per billion (for resistive semiconductor regions) to a fraction of a percent (for
highly conductive regions).
An epoxy power discrete package for power MOSFETs, IGBTs, and bipolar transistors. The
D-pack is available in a straight leaded version (TO-251) or a surface mountable version
(TO-252).
One of the three regions that form a field-effect transistor. Majority carriers that
originate at the source and traverse the channel are collected at the drain to complete
the current path. The flow between source and drain is controlled by the voltage applied
to the gate. See also channel, FET, gate and source.
Dynamic Random Access Memory. The lowest cost and most
popular type of semiconductor read/write memory chip, in which the presence or absence of
a capacitive charge represents the state of a binary storage element (zero or one). The
charge must be periodically refreshed. Pronounced "dee-ram".
Design Rule Check. DRCs measure spacing, overlap, and sizes of all
masking dimensions on the layout. This is necessary to ensure that the circuit dimensions
will conform to the capabilities of the fabrication process.
Typically, an electronic function used to provide amplification to drive high current
loads. Term often used to denote bus drivers that rapidly charge and discharge
capacitance. Also used to denote the ability to control power, such as when driving a
solenoid or other high-current device.
Digital-Signal Processing. Digital circuits designed to address a
broad class of problems in signal reception and analysis that have traditionally been
solved using analog components. DSP is rapidly replacing analog signal processing
functions where requirements for stability over time and temperature variations are
critical. DSP is used to enhance, analyze, filter, modulate, or otherwise manipulate
standard real-world functions, such as images, sounds, radar pulses, and other such
signals by analyzing and transforming wave-forms (e.g., transmitting data over phone lines
via modem). Intersil offers building blocks and special function chips for DSP, including
fast multipliers, multiplier accumulators, image processors, histogrammers, and digital
filters.
See DIP.
Defect and Yield Management. See yield.
