Schottky-Drain Technology for AlGaN/GaN High-Electron Mobility Transistors

Dept. of Electr. Eng. & Comput. Sci., Massachusetts Inst. of Technol., Cambridge, MA, USA
IEEE Electron Device Letters (Impact Factor: 2.79). 05/2010; DOI:10.1109/LED.2010.2040704
Source: IEEE Xplore

ABSTRACT In this letter, we demonstrate 27% improvement in the buffer breakdown voltage of AlGaN/GaN high-electron mobility transistors (HEMTs) grown on Si substrate by using a new Schottky-drain contact technology. Schottky-drain AlGaN/GaN HEMTs with a total 2-??m-thick GaN buffer showed a three-terminal breakdown voltage of more than 700 V, while conventional AlGaN/GaN HEMTs of the same geometry showed a maximum breakdown voltage below 600 V. The improvement of the breakdown voltage has been associated with the planar contact morphology and lack of metal spikes in the Schottky-drain metallization.

0 0
1 Bookmark
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: In this letter, we present a new technology to increase the breakdown voltage of AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on Si substrates. This new technology is based on the removal of the original Si substrate and subsequent transfer of the AlGaN/GaN HEMT structure to an insulating carrier wafer (e.g., glass or polycrystalline AlN). By applying this new technology to standard AlGaN/GaN HEMTs grown on Si substrate, an AlGaN/GaN HEMT with breakdown voltage above 1500 V and specific on resistance of 5.3 mΩ·cm<sup>2</sup> has been achieved.
    IEEE Electron Device Letters 10/2010; · 2.79 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Silicon carbide (SiC) semiconductor devices for high power applications are now commercially available as discrete devices. Recently Schottky diodes are offered by both USA and Europe based companies. Active switching devices such as bipolar junction transistors (BJTs), field effect transistors (JFETs and MOSFETs) are now reaching the market. The interest is rapidly growing for these devices in high power and high temperature applications. The main advantages of wide bandgap semiconductors are their very high critical electric field capability. From a power device perspective the high critical field strength can be used to design switching devices with much lower losses than conventional silicon based devices both for on-state losses and reduced switching losses. This paper will review the current state of the art in active switching device performance for both SiC and GaN devices. SiC material quality and epitaxy processes have greatly improved and degradation free 100 mm wafers are readily available. This is encouraging since also bipolar devices now are attractive with good long term stability. SiC wafers still have a too high cost to be fully cost efficient. However, the SiC wafer roadmap looks very favorable as volume production takes off. For GaN materials the main application area is geared towards the lower power rating level up to 1 kV on mostly lateral FET designs. The cost advantage is interesting for GaN when grown on Si substrates to bring down costs.
    Sciece China. Information Sciences 01/2011; 54:1087-1093. · 0.71 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Between 5 and 10% of the world's electricity is wasted as dissipated heat in the power electronic circuits needed, for example, in computer power supplies, motor drives or the power inverters of photovoltaic systems. This paper describes how the unique properties of GaN enables a new generation of power transistors has the potential to reduce by at least an order of magnitude the cost, volume and losses of power electronic systems. We will describe three key technologies: Schottky drain contacts and substrate removal to increase the breakdown voltage, and a dual-gate device with superior enhancement-mode characteristics.


Available from