COOLMOS/sup TM/-a new milestone in high voltage power MOS
26 May 1999-pp 3-10
TL;DR: The CoolMOS/sup TM/ as discussed by the authors, a new high voltage power MOSFET based on the concept of charge compensation, has been introduced, which shows both a very small input capacitance and a strongly nonlinear output capacitance.
Abstract: Recently, a new technology for high voltage power MOSFETs has been introduced: the CoolMOS/sup TM/. Based on the new device concept of charge compensation, the R/sub DS(on)/ area product for e.g. 600 V transistors has been reduced by a factor of 5. The devices show no bipolar current contribution like the well known tail current observed during the turn-off phase of IGBTs. CoolMOS/sup TM/ virtually combines the low switching losses of a MOSFET with the on-state losses of an IGBT. Furthermore, the dependence of R/sub DS(on)/ on the breakdown voltage has been redefined. The more than square-law dependence in the case of standard MOSFET has been broken and a linear voltage dependence achieved. This opens the way to new fields of application even without avalanche operation. System miniaturization, higher switching frequencies, lower circuit parasitics, higher efficiency, and reduced system costs are pointing the way towards future developments. Not only has the new technology achieved breakthrough at reduced R/sub DS(on)/ values, but new benchmarks have also been set for the device capacitances. Due to chip shrinkage and a novel internal structure, the technology shows both a very small input capacitance and a strongly nonlinear output capacitance. The drastically lower gate charge facilitates and reduces the cost of controllability, and the smaller feedback capacitance reduces the dynamic losses. With this new technology, the minimum R/sub DS(on)/ values in all packages are being redefined in the important 600-1000 V categories.
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07 Nov 2002
TL;DR: The benefits of using SiC in power electronics applications are looked at, the current state of the art of SiC is reviewed, and how SiC can be a strong and viable candidate for future power electronics and systems applications are shown.
Abstract: Silicon offers multiple advantages to power circuit designers, but at the same time suffers from limitations that are inherent to silicon material properties, such as low bandgap energy, low thermal conductivity, and switching frequency limitations. Wide bandgap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), provide larger bandgaps, higher breakdown electric field, and higher thermal conductivity. Power semiconductor devices made with SiC and GaN are capable of higher blocking voltages, higher switching frequencies, and higher junction temperatures than silicon devices. SiC is by far the most advanced material and, hence, is the subject of attention from power electronics and systems designers. This paper looks at the benefits of using SiC in power electronics applications, reviews the current state of the art, and shows how SiC can be a strong and viable candidate for future power electronics and systems applications.
454 citations
Cites background from "COOLMOS/sup TM/-a new milestone in ..."
...MOSFETs have been hindered for a long time by their relatively high conduction losses due to their high on-state resistance, . As the blocking voltage (BV) increases, so does their on-state resistance , hence, making MOSFETs less attractive for high-voltage applications (beyond 600 V). Recent enhancements in power MOSFET technology such as the CoolMOS [ 12 ] allow for substantial reduction of the conduction losses....
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TL;DR: The importance of power electronics, the recent advances of power semiconductor devices, converters, variable-frequency AC drives, and advanced control and estimation techniques will be reviewed briefly.
Abstract: Power electronics technology has gone through dynamic evolution in the last four decades. Recently, its applications are fast expanding in industrial, commercial, residential, transportation, utility, aerospace, and military environments primarily due to reduction of cost, size, and improvement of performance. In the global industrial automation, energy conservation, and environmental pollution control trends of the 21st century, the widespread impact of power electronics is inevitable. It appears that the role of power electronics on our society in the future will tend to be as important and versatile as that of information technology today. In this paper, the importance of power electronics will be discussed after a brief historial introduction in the beginning. Then, the recent advances of power semiconductor devices, converters, variable-frequency AC drives, and advanced control and estimation techniques will be reviewed briefly. Unlike a traditional technology survey paper, the number of figures is kept intentionally small in favor of the text within the length constraint of this paper. The prognosis of different areas will be highlighted wherever possible based on the author's own knowledge and experience. In conclusion and future scenario, the trend of power electronics and motor drives along with some possible research and development areas will be highlighted.
401 citations
Cites background from "COOLMOS/sup TM/-a new milestone in ..."
...Recently, high-voltage (up to 800 V) CoolMOS devices have been introduced by Infineon Technology [23] based on Super Junction design, where the conduction loss has been cut down substantially in comparison with that of the normal device....
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TL;DR: The merits and limitations of several PFC techniques used in today's network-server and telecom power supplies to maximize their conversion efficiencies are discussed, and the effect of recent advancements in semiconductor technology on the performance and design considerations of PFC converters is discussed.
Abstract: A review of high-performance, state-of-the-art, active power-factor-correction (PFC) techniques for high-power, single-phase applications is presented. The merits and limitations of several PFC techniques that are used in today's network-server and telecom power supplies to maximize their conversion efficiencies are discussed. These techniques include various zero-voltage-switching and zero-current-switching, active-snubber approaches employed to reduce reverse-recovery-related switching losses, as well as techniques for the minimization of the conduction losses. Finally, the effect of recent advancements in semiconductor technology, primarily silicon-carbide technology, on the performance and design considerations of PFC converters is discussed.
350 citations
Additional excerpts
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TL;DR: The superjunction concept is compared to other methods of enhancing the conductivity of power devices (from bipolar to employment of wide-bandgap materials) to derive its set of benefits and limitations.
Abstract: Superjunction has arguably been the most creative and important concept in the power device field since the introduction of the insulated gate bipolar transistor (IGBT) in the 1980s. It is the only concept known today that has challenged and ultimately proved wrong the well-known theoretical study on the limit of silicon in high-voltage devices. This paper deals with the history, device and process development, and the future prospects of Superjunction technologies. It covers fundamental physics, technological challenges as well as aspects of design and modeling of unipolar devices, such as CoolMOS. The superjunction concept is compared to other methods of enhancing the conductivity of power devices (from bipolar to employment of wide-bandgap materials) to derive its set of benefits and limitations. This paper closes with the application of the superjunction concept to other structures or materials, such as terminations, superjunction IGBTs, or silicon carbide Field Effect Transistors (FETs).
244 citations
Cites background or methods from "COOLMOS/sup TM/-a new milestone in ..."
...MOSFET AND A 600 V RATED MOSFET—ADAPTED FROM [9]...
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...In Table I [9], examples of the approximate contributions of each of these resistances for two planar devices, one designed...
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...THE concept of superjunction devices was introduced in the patent field in the 1980s and 1990s [2]–[7], with its first invention dating from 1978 [1], but its technological realization took place only in the late 1990s [8] with Infineon and ST Microelectronics leading the way, with their two trademark products CoolMOS [8], [9] and MDMesh [10], respectively....
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...One of the first vertical devices using a superjunction-based principle was proposed as early as 1980 in [20] and the commercial products based on this were introduced as CoolMOS [8], [9] and MDMESH [10] in the late 1990s....
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Patent•
29 Nov 2000TL;DR: In this paper, an electrically insulating region lines the first sidewall of the first trench and has a nonuniform thickness T ins (y) in a range between about 0.5 and 1.5 times T ideal (y).
Abstract: Power semiconductor devices having tapered insulating regions include a drift region of first conductivity type therein and first and second trenches in the substrate. The first and second trenches have first and second opposing sidewalls, respectively, that define a mesa therebetween into which the drift region extends. An electrically insulating region having tapered sidewalls is also provided in each of the trenches. The tapered thickness of each of the electrically insulating regions enhances the degree of uniformity of the electric field along the sidewalls of the trenches and in the mesa and allows the power device to support higher blocking voltages despite a high concentration of dopants in the drift region. In particular, an electrically insulating region lines the first sidewall of the first trench and has a nonuniform thickness T ins (y) in a range between about 0.5 and 1.5 times T ideal (y), where T ideal (y)| y≧α =e ins ((2e s E cr /qW m N d )(Y−α)−¼W m )e s and e ins is the permittivity of the electrically insulating region, e s is the permittivity of the drift region, E cr is the breakdown electric field strength of the drift region, q is the electron charge, N d is the first conductivity type doping concentration in the drift region, W m is a width of the mesa, y is the depth, relative to a top of the first trench, at which the thickness of the electrically insulating region is being determined and α is a constant. The constant a may equal zero in the event the power device is a Schottky rectifier and may equal the depth of the P-base region/N-drift region junction in the event the power device is a vertical MOSFET.
141 citations
References
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06 Dec 1998
TL;DR: In this article, the authors proposed a new device concept for high voltage power devices based on charge compensation in the drift region of the transistor, which achieved a shrink factor of 5 versus the actual state of the art in power MOSFETs.
Abstract: For the first time a new device concept for high voltage power devices has been realized in silicon. Our 600 V-COOLMOS/sup TM/ reaches an area specific on-resistance of typically 3.5 /spl Omega//spl middot/mm/sup 2/. Our technology thus offers a shrink factor of 5 versus the actual state of the art in power MOSFETs. The device concept is based on charge compensation in the drift region of the transistor. We increase the doping of the vertical drift region roughly by one order of magnitude and counterbalance this additional charge by the implementation of fine structured columns of the opposite doping type. The blocking voltage of the transistor remains thus unaltered. The charge compensating columns do not contribute to the current conduction during the turn-on state. Nevertheless the drastically increased doping of the drift region allows the above mentioned reduction of the on-resistance.
464 citations