Silicon on Sapphire

Silicon on Sapphire

Silicon on Sapphire wafers are comprised of R-Plane (1102) sapphire wafers with a deposited layer of silicon on their polished surface.

When cut at the R-plane the oxygen atoms of the sapphire wafer mirror the symmetry of the silicon crystal at (100) orientation enough that silicon crystal can be grown on the surface.

Silicon on Sapphire wafers are used in radio frequency integrated circuits (RFIC). Chips made using Silicon-on-Sapphire are used in mobile devices and other electronics where the low power consumption, resistance to radiation and durability and stability over a wide temperature range allow them to out-perform other Silicon-on-Insulator devices.

Standard Specification

Item Specification
Substrate Diameter 3" 4" 6" 8"
Material 99.996% Purity Single Crystal Al2O3 (Sapphire)
Grade Prime, Epi-ready
Orientation R-Plane (1-102), (10-12), (0112)
Off-Cut +/-1.0 degree +/- 0.5 degree +/-1.0 degree +/-20 degree
Diameter (mm) 76.0 (+/-0.5mm) 100 (+/-0.2mm) 150mm (+/-0.3mm) 200mm (+/-0.5mm)
Thickness (um) 350/500 (+/-20um) 460/530 (+/-20um) 600 (+/-20um) 725 (+/-20um)
Primary Flat 45degree Counter-Clockwise from Axis C projection on R-plane
Flat Length (mm) 22.0 (+/-3.0mm) 32.5 (+/-2.5mm) 47.5/57.5 (+/-2.5mm) Notch per SEMI M1-1105
Front Surface Epi-Ready Polished Surface Ra ≤0.3nm
Back Surface Finish as lapped (Ra =0.6um) or Optical Polish
Laser Marking SEMI Standard LM on back of wafer
TTV ≤25um ≤15um ≤12um ≤20um
BOW ≤25um ≤20um ≤30um ≤20um
WARP ≤25um ≤20um ≤30um ≤40um
Flatness ≤20um ≤12um ≤8um ≤15um
Packaging SEMI Standard, Argon Atmosphere vacuum sealed in class 100 clean room
Edge Exclusion (mm) 2 3 4 5
Notes Metallic Contamination: <5e10 atoms/cm² by VPD for Ca, Na, K, Cr, Zn, Fe, Cu and Ni;LPD:≤40 @ ≥0.2microns
EPI Layer Thickness Silicon Epi Layer centre point: 0.1~6.0um
Si (100) Epi on R-Plane Sapphire Polished Side
Si layer epitaxially deposited directly onto sapphire substrate in accordance with SEMI M4-1296
Intrinsic (Non intentionally doped) type; N-tye(Phos. Doped); P-type (Boron Doped)
0.1~100Ωcm or ≤100Ωcm
(for particles greater than 2 microns): < 2 per cm²

For R-Plane sapphire wafers please see our sapphire wafer section.