3.Definitions of Silicon Carbide Epitaxy

3-1. Large Point Defects

3-1. Large Point Defects Defects which exhibit a clear shape to the unassisted eye and are > 50 microns across. These features include spikes, adherent particles, chips and craters. Large point defects less than 3 mm apart count as one defect.

3-2. Scratches

3-2. Scratches Grooves or cuts below the surface plane of the wafer having a length-to-width ratio of greater than 5 to 1. Scratches are speci ed by the number of discrete scratches times the total length in fractional diameter.  

3-3. Dimpling

3-3. Dimpling A texture resembling the surface of a golf ball. Speci ed in % affected area.

3-4. Step Bunching

3-4. Step Bunching Step bunching is visible as a pattern of parallel lines running perpendicular to the major  at. If present, estimate the % of speci ed area affected.  

3-5. Backside Cleanliness

3-5. Backside Cleanliness Veri ed by inspecting for a uniform color to the wafer backside. Note there is a darker region near the center of some higher doped wafers. Backside cleanliness speci ed as percent area clean.  

3-6. Edge Chips

3-6. Edge Chips Areas where material has been unintentionally removed from the wafer.Do not confuse fractures in epi crown with edge chips.  

3-8. 3C Inclusions

3-8. 3C Inclusions Regions where step- ow was interrupted during epi layer growth. Typical regions are generally triangular although more rounded shapes are sometimes seen. Count once per occurrence. Two inclusions within 200 microns count as one.  

3-9. Comet Tails

3-9. Comet Tails Comet tails have a discrete head and trailing tail. These features are aligned parallel to the major  at. Usually, all comet tails tend to be of the same length. Count once per occurrence. Two comet tails within 200 microns count as one.  

3-10. Carrots

3-10. Carrots Similar to comet tails in appearance except they are more angular and lack a discrete head. If present, these features are aligned parallel to the major  at. Usually,any carrots present tend to be of the same length. Count once per occurrence. Two carrots within 200 microns count [...]