S. Matsunaga

Fuji Electric Co., Edo, Tokyo, Japan

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Publications (7)

  • Mutsumi Sawada · Masaharu Yamaji · Shinichiro Matsunaga · [...] · Naoto Fujishima
    [Show abstract] [Hide abstract] ABSTRACT: Trench lateral power MOSFETs (TLPMs) are suitable for one chip power ICs due to its low specific on- resistance and ease of fabrication with CDMOS devices. In our smart power IC process we integrated both the high side n- channel and bidirectional TLPMs in one chip. In addition, better device characteristics of both devices were obtained with the process integration technology. The high side MOSFET shows 20 mOmegamm<sup>2</sup> specific on-resistance with 25 V breakdown voltage and excellent reliability. The bidirectional MOSFET shows 7.0 mOmegamm<sup>2</sup> specific on-resistance, which represents 67% of the current mass production value, with a breakdown voltage of 25 V.
    Conference Paper · Jun 2008
  • S Matsunaga · M. Sawada · M. Sugimoto · N. Fujishima
    [Show abstract] [Hide abstract] ABSTRACT: Parasitic diode is frequently employed in integrated power devices, and causes parasitic leakage current. Large leakage current may cause troubles, such as latch up, malfunction of analogue circuit and increase in consumption power. In a single chip Li-ion battery protection IC, new operation method to charge a battery without using the parasitic diode is devised. To detect current direction precisely, only half of the bi-directional switches are turned on. We call it 'half on' operation. This operation suppresses parasitic current and heat generation. The parasitic current is reduced from a few milli-amperes to a few nano- amperes. Chip temperature during charging can be lowered from 190 to 65 degrees Celsius.
    Conference Paper · Jun 2007
  • [Show abstract] [Hide abstract] ABSTRACT: We developed a battery protection IC integrating a low specific on-resistance bi-directional trench lateral power MOSFET (BTLPM). In the bi-directional switches, two MOSFETs share a drain region and there is neither drain contact nor drain metal wire. The developed bi-directional switches have a breakdown voltage of 23V and a specific on-resistance of 6.8mΩmm2 per one side MOSFET. Wafer-level Chip Size Package (W-CSP) is utilized, and the chip mounting area can be reduced to 3mm2, which is less than one-third of conventional multi-chip system. Parasitic wire resistance is also reduced to 5.3mΩ, which is about one-seventh of that of conventional package without thick copper layer.
    Article · Jan 2007 · IEEJ Transactions on Industry Applications
  • S. Matsunaga · M. Sawada · A. Sugi · [...] · N. Fujishima
    [Show abstract] [Hide abstract] ABSTRACT: A low gate charge high-side N-channel trench lateral power MOSFET (TLPM) is developed. Using trench self-aligning structure, a short gate length and minimum gate-drain overlap are realized, and low gate charge is achieved. The product of on-resistance and gate charge Ron*Qg of 61mOmega*nC (Ron*Qgd of 16.4 mOmega*nC) is the lowest for 20V class integrated device. Thanks to the deep junction depth of N drift region, TLPM has good electrostatic discharge (ESD) tolerance, which is a weak point of conventional lightly doped drain (LDD) MOS. TLPM withstands 2kV pulse test at human body model (HBM) and 200V pulse tests at machine model (MM)
    Conference Paper · Jul 2006
  • [Show abstract] [Hide abstract] ABSTRACT: A low specific on-resistance bi-directional trench lateral power MOSFET (BTLPM) has been integrated with a controller in a 0.6mum BiCDMOS process for single-cell lithium-ion battery protector, downsizing the footprint of the protector in chip-scale package to 3mm <sup>2</sup>, one-third of its multi-chip counterparts. The first-silicon results of the BTLPM switches demonstrated a breakdown voltage of 22V, a specific on-resistance of 6.8mOmegamm<sup>2</sup> at a gate voltage of 4V (a gate electrical field of 2.3MV/cm)
    Conference Paper · Jun 2005
  • [Show abstract] [Hide abstract] ABSTRACT: A trench lateral power MOSFET (TLPM) has a unique structure. The gate is formed on the trench sidewall, and the drain is connected with metal wire at the bottom of the trench. This structure enables high device density compared to conventional lateral DMOSs. A p-channel TLPM for high side switches has been first integrated. A specific on-resistance of 28 mΩ - mm<sup>2</sup> with a breakdown voltage of 35 V has been realized. This is the best specific on-resistance in this voltage class for a p-channel lateral power MOSFET embedded with logic devices. P-channel, n-channel TLPM devices and a 0.6 μm bi-CMOS are fabricated on the same silicon wafer, thus a synchronous switching converter can be implemented on a single chip.
    Conference Paper · Jul 2004
  • [Show abstract] [Hide abstract] ABSTRACT: We proposed a low side N-channel trench lateral power MOSFET (TLPM) in (N.Fujishima et al, Proc. of IEDM 2002, p.455-458). In this paper, a high side N-channel TLPM, which is isolated from the substrate, is proposed, fabricated and characterized for the first time. The fabricated high side TLPM devices exhibit a specific on-resistance of 17 mΩ-mm<sup>2</sup> with a breakdown voltage of 21 V.
    Conference Paper · Jun 2004