150mm Silicon Carbide Selective Embedded Epitaxial Growth Technology by CVD

Abstract

In this work, we have developed a selective embedded epitaxial growth process on 150-mm-diameter wafer by vertical type hot wall CVD reactor with the aim to realize the all-epitaxial 4H-SiC MOSFETs [1, 2, 3, 4, 5]. We found that at elevated temperature and adding HCl, the epitaxial growth rate at the bottom of trench is greatly enhanced compare to growth on the mesa top. And we obtain high growth rate 7.6μm/h at trench bottom on 150mm-diameter-wafer uniformly with high speed rotation (1000rpm).

CVD Filling of Narrow Deep 4H-SiC Trenches in a Quasi-Selective Epitaxial Growth Mode

“…However, to fill a trench deeper than 5 μm which takes a long growth duration, merely reviewing R G-TB is thought to be inadequate, since the epilayer on mesa grown at R G-MT >0 perhaps closes the trench during the long growth duration. To make an overall evaluation of all aspects, a growth ratio factor of filling process is formulated, which is defined as η Fill =R G-TB /(R G-MT +R G-TB ) [9]. Figure 1(c) shows a growth ratio factor map attained on 5-μm trenches.…”

Selection of ion species suited for channeled implantation to be used in multi-epitaxial growth for SiC superjunction devices

“…After correction: , where 46-keV 11 B, 59-keV 14 N, 114 keV 27 Al, and 131-keV 31 P ions were implanted at a dose of 1.3 × 10 13 cm −2 . Maximum channeled range (R max ) is defined as the depth where concentration decreases to 10% of its channeled peak concentration.…”

“…6. (Color online) Secondary-ion mass spectrometry measured depth profiles of channeled-ion implantations into 4H-SiC (0001) at a velocity of 9 × 10 7 cm −2 , where 46-keV 11 B, 59-keV 14 N, 114-keV 27 Al, and 131-keV Before correction:…”

“…Although a trench-etching-and-sidewall-implant method has been used to fabricate 1.35-kV SiC SJ Schottky diodes, 7,8) an increase in BV (i.e., trench depth > 6 μm) is limited by the difficulty in the sidewall implant with an incident angle more than 70°. 7,8) Large BV can be attained using a trench-filling epitaxial growth method; [9][10][11][12][13][14][15] however, complete filling of SiC around the trench edge has yet to be attained. 16) In contrast, a multiepitaxial growth method (ME), in which epitaxial growth and ion implantation are repeated alternately until a certain driftlayer thickness is achieved, has been successfully employed; namely, 1.54-kV SJ p-n diodes 17) and 0.82-kV SJ V-groove trench MOSFETs 18) fabricated using 9 MeV Al-ion implantation, as well as 1.17-kV SJ V-groove trench MOSFETs 19) and 1.2 kV-class SJ trench MOSFETs 20) fabricated using sub-MeV Al-ion implantation.…”

Origin of Large Bumps Abnormally Grown on 4H-SiC Epitaxial Film by Adding HCl Gas with High Cl/Si Ratio in CVD Process

“…Recently, epitaxial growth technology towards selective growth of 4H-SiC epitaxial film to realize high performance power devices with trench structure has been investigated. It has been reported that the 4H-SiC epitaxial film is satisfactorily filled in the trench by adding HCl gas with a high Cl/Si ratio of about 30 in CVD process [1,2]. However, most of previous reports have been focused on filling characteristics of the SiC in the trench, and defect formation on the planar substrate grown at the same condition has not been investigated.…”