Wolfspeed is transitioning to a new wafer scribe format based upon SEMI specification M12-0706. This conversion, which is projected to be fully integrated in 2022, brings several improvements. The M12-based scribe will be positioned upright when the major flat or notch is oriented up, making the scribe easier to read when the wafers are loaded into cassettes. The new format includes a wafer supplier identification code, validating the wafer’s authenticity. It also includes a checksum, which is an error-detection method that prevents OCR mis-read errors and reduces the instance of processing errors associated with such event.
With more than 30 years of development and manufacturing experience, Wolfspeed is driving innovation with the industry’s broadest range of SiC and GaN materials. Delivering semi-insulating substrates and nitride epitaxy options up to the newly available diameter of 150mm, Wolfspeed materials enable performance far exceeding that of any other technology, for telecom, aerospace, or defense applications with world-leading bandwidth, efficiency and frequency of operation.
When you partner with Wolfspeed, you get the best and most innovative materials.
Wolfspeed produces GaN, AlxGa1-xN and Al1-yInyN epitaxial layers on SiC substrates. Unless noted otherwise on the product quotation, the epitaxial layer structure will meet or exceed the following specifications (1). Contact Wolfspeed Materials Sales for specification on custom epitaxy requests. Additional comments, terms and conditions may be found in the specification document.
Property | Value or Range | Precision | Measurement Technique |
|---|---|---|---|
Substrate | On-axis SiC (Semi-Insulating) | - | - |
Composition (2) | AlxGa1-xN or Al1-yInyN 0 ≤ x ≤ 0.3, 0 ≤ y ≤ 0.2, certain restrictions apply | Δ x = ± 0.015 Δ y = ± 0.02 | XRD peak splitting |
Thickness (3) | 1.0 μm to 3.0 μm GaN 0.5 nm to 1.0 μm AlN 1.0 nm to 1.0 μm AlxGa1-xN 1.0 nm to 1.0 μm Al1-yInyN 2.0 nm to 5.0 nm GaN (Cap Layer) 5.0 nm to 100 nm SiN (Cap Layer) | Average thickness within ± 15% of target thickness and uniformity <10%. (4) | X-ray or white light interferometry |
GaN Crystallinity | < 250 arcsec (3 μm layer on SiC substrate) | - | XRD (0006) FWHM (center point) |
Al0.25Ga0.75N | < 500 arcsec (3 μm layer on SiC substrate) | - | XRD (0006) FWHM (center point) (5) |
Visible Defects | < 50/cm2 | - | Differential interference microscopy at 50x in cross pattern with 5 mm edge exclusion |
Property | Value or Range | Precision | Measurement Technique |
|---|---|---|---|
Dopant type | n-type (Si) HEMT buffer (Fe and/or C) | - | - |
Carrier concentration (unintentionally doped) | < 1E16/cm3, n-type | - | CV |
Carrier concentration (n-type, Si doped) | 1E16 to 2E19/cm3 | ± 50% | CV (wafer center, room temperature) |
Carrier concentration of HEMT structure | >8E12/cm2 (25 nm Al0.25Ga0.75N) | - | Contactless non-destructive carrier concentration |
Mobility of HEMT structure | μ ≥ 1500 cm2 V-1 s-1 (25 nm Al0.25Ga0.75N) | - | Contactless non-destructive mobility |
Sheet resistivity | < 5% uniformity | - | Contactless non-destructive sheet resistivity |
Notes:
