A fully planarized 4H-SiC trench MOS barrier Schottky (TMBS) rectifier

Abstract

A fully planarized 4H-SiC trench MOS barrier Schottky (TMBS) rectifier has been designed, fabricated and characterized for the first time. The use of a TMBS structure helps improve the reverse leakage current by more than three orders of magnitude compared to that of a planar Schottky rectifier. We have achieved a low reverse leakage current density of 6 10 6 A/cm 2 and a low forward voltage drop of 1.75 V at 60 A/cm 2 for the TMBS rectifier. The static current-voltage (I-V) and switching characteristics of the TMBS rectifier have been measured at various temperatures. A barrier height of 1.0 eV and an ideality factor of 1.8 were extracted from the forward characteristics. The switching characteristics do not change with temperature indicating the essential absence of stored charge.

Silicon Carbide Schottky Barrier Diode

“…In order to reduce the reverse leakage current of SiC SBDs, various methods have been proposed through the years [116,[124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141]. These include the Junction Barrier Schottky In Table 6, various structures reported to reduce the reverse leakage current and increase on-off current ratio of the SBD are listed through recently years.…”

Temperature dependence of current-and capacitance–voltage characteristics of an Au/4H-SiC Schottky diode

“…The number of studies over electrical, optical properties and device applications of SiC keeps increasing in the electronic materials based on SiC Schottky diode. In consequence, the fabrication of electronic devices such as thyristors, metal-oxide-semiconductor field effect transistors (MOSFETS), pin diodes, insulated gate bipolar transistors (IGBTS) including SiC are processed successfully [5,[7][8][9][10].…”

Investigation on barrier inhomogeneities in 4H‐SiC Schottky rectifiers

“…Micropipes are the device killing defects [16] and high density of screw dislocations may cause deterioration in reverse characteristics when the electric field reaches a critical value, but they were not the major factors responsible for SBH inhomogeneities [14,15]. Despite the difficulty in identifying the source defects of SBH inhomogeneities, various device structures [17][18][19][20][21] and thermal annealing processes [22][23][24] have been developed to reduce the reverse leakage current. One main idea is to develop a structure to pinch off the low SBH region by a high SBH, such as Junction Barrier Schottky (JBS) structure [17], MOS structure [18], dual-metal [19], and trench MOS barrier [20], etc.…”

“…Despite the difficulty in identifying the source defects of SBH inhomogeneities, various device structures [17][18][19][20][21] and thermal annealing processes [22][23][24] have been developed to reduce the reverse leakage current. One main idea is to develop a structure to pinch off the low SBH region by a high SBH, such as Junction Barrier Schottky (JBS) structure [17], MOS structure [18], dual-metal [19], and trench MOS barrier [20], etc. However, these solutions usually do not have significant impact on eliminating the SBH inhomogeneities [21].…”