4H N Type SiC Semiconductor Wafer, Dummy Grade,3”Size
PAM-XIAMEN offers semiconductor silicon carbide wafers,6H SiC and 4H SiC in different quality grades for researcher and industry manufacturers. We has developed SiC crystal growth technology and SiC crystal wafer processing technology,established a production line to manufacturer SiCsubstrate,Which is applied in GaNepitaxydevice,powerdevices,high-temperature device and optoelectronic Devices. As a professional company invested by the leading manufacturers from the fields of advanced and high-tech material research and state institutes and China’s Semiconductor Lab,weare devoted to continuously improve the quality of currently substrates and develop large size substrates.
Here shows detail specification:
SILICON CARBIDE MATERIAL PROPERTIES
Polytype | Single Crystal 4H | Single Crystal 6H |
Lattice Parameters | a=3.076 Å | a=3.073 Å |
c=10.053 Å | c=15.117 Å | |
Stacking Sequence | ABCB | ABCACB |
Band-gap | 3.26 eV | 3.03 eV |
Density | 3.21 · 103 kg/m3 | 3.21 · 103 kg/m3 |
Therm. Expansion Coefficient | 4-5×10-6/K | 4-5×10-6/K |
Refraction Index | no = 2.719 | no = 2.707 |
ne = 2.777 | ne = 2.755 | |
Dielectric Constant | 9.6 | 9.66 |
Thermal Conductivity | 490 W/mK | 490 W/mK |
Break-Down Electrical Field | 2-4 · 108 V/m | 2-4 · 108 V/m |
Saturation Drift Velocity | 2.0 · 105 m/s | 2.0 · 105 m/s |
Electron Mobility | 800 cm2/V·S | 400 cm2/V·S |
hole Mobility | 115 cm2/V·S | 90 cm2/V·S |
Mohs Hardness | ~9 | ~9 |
4H N Type SiC Semiconductor Wafer, Dummy Grade,3”Size
SUBSTRATE PROPERTY | S4H-51-SI-PWAM-250 S4H-51-SI-PWAM-330 S4H-51-SI-PWAM-430 |
Description | Dummy Grade 4H SEMI Substrate |
Polytype | 4H |
Diameter | (50.8 ± 0.38) mm |
Thickness | (250 ± 25) μm (330 ± 25) μm (430 ± 25) μm |
Resistivity (RT) | >1E5 Ω·cm |
Surface Roughness | < 0.5 nm (Si-face CMP Epi-ready); <1 nm (C- face Optical polish) |
FWHM | <50 arcsec |
Micropipe Density | A+≤1cm-2 A≤10cm-2 B≤30cm-2 C≤50cm-2 D≤100cm-2 |
Surface Orientation | |
On axis <0001>± 0.5° | |
Off axis 3.5° toward <11-20>± 0.5° | |
Primary flat orientation | Parallel {1-100} ± 5° |
Primary flat length | 16.00 ± 1.70 mm |
Secondary flat orientation Si-face:90° cw. from orientation flat ± 5° | |
C-face:90° ccw. from orientation flat ± 5° | |
Secondary flat length | 8.00 ± 1.70 mm |
Surface Finish | Single or double face polished |
Packaging | Single wafer box or multi wafer box |
Usable area | ≥ 90 % |
Edge exclusion | 1 mm |
SiC crystal growth
Bulk crystal growth is the technique for fabrication of single crystalline substrates , making the base for further device processing.To have a breakthrough in SiC technology obviously we need production of SiC substrate with a reproducible process.6H- and 4H- SiC crystals are grown in graphite crucibles at high temperatures up to 2100—2500°C. The operating temperature in the crucible is provided either by inductive (RF) or resistive heating. The growth occurs on thin SiC seeds. The source represents polycrystalline SiC powder charge. The SiC vapor in the growth chamber mainly consists of three species, namely, Si, Si2C, and SiC2, which are diluted by carrier gas, for example, Argon. The SiC source evolution includes both time variation of porosity and granule diameter and graphitization of the powder granules.
High-Power Device Operation
The high breakdown field and high thermal conductivity of SiC coupled with high operational junction
temperatures theoretically permit extremely high-power densities and efficiencies to be realized in SiC
devices. The high breakdown field of SiC relative to silicon enables the blocking voltage region of a
power device to be roughly 10×thinner and 10×heavier doped, permitting a roughly 100-fold
beneficial decrease in the blocking region resistance at the same voltage rating. Significant energy
losses in many silicon high-power system circuits, particularly hard-switching motor drive and power
conversion circuits, arise from semiconductor switching energy loss . While the physics of
semiconductor device switching loss are discussed in detail elsewhere, switching energy loss is
often a function of the turn-off time of the semiconductor switching device, generally defined as the
time lapse between application of a turn-off bias and the time when the device actually cuts off most
of the current flow. In general, the faster a device turns off, the smaller its energy loss in a switched
power conversion circuit. For device-topology reasons discussed in References 3,8, and 19–21, SiC’s
high breakdown field and wide energy bandgap enable much faster power switching than is possible
in comparably volt–ampere-rated silicon power-switching devices. The fact that high-voltage operation
is achieved with much thinner blocking regions using SiC enables much faster switching (for comparable
voltage rating) in both unipolar and bipolar power device structures. Therefore, SiC-based power
converters could operate at higher switching frequencies with much greater efficiency (i.e., less switching
energy loss). Higher switching frequency in power converters is highly desirable because it
permits use of smaller capacitors, inductors, and transformers, which in turn can greatly reduce overall
power converter size, weight, and cost.
While SiC’s smaller on-resistance and faster switching helps minimize energy loss and heat generation,
SiC’s higher thermal conductivity enables more efficient removal of waste heat energy from the active
device. Because heat energy radiation efficiency increases greatly with increasing temperature difference
between the device and the cooling ambient, SiC’s ability to operate at high junction temperatures permits
much more efficient cooling to take place, so that heat sinks and other device-cooling hardware (i.e., fan
cooling, liquid cooling, air conditioning, heat radiators, etc.) typically needed to keep high-power devices
from overheating can be made much smaller or even eliminated.
While the preceding discussion focused on high-power switching for power conversion, many of the
same arguments can be applied to devices used to generate and amplify RF signals used in radar and
communications applications. In particular, the high breakdown voltage and high thermal conductivity
coupled with high carrier saturation velocity allow SiC microwave devices to handle much higher power
densities than their silicon or GaAs RF counterparts, despite SiC’s disadvantage in low-field carrier
mobility.