Semiconductor device—Non-destructive recognition criteria of defects in silicon carbide homoepitaxial wafer for power devices—Part 1: Classification of defects
Semiconductor device - Non-destructive recognition criteria of defects in silicon carbide homoepitaxial wafer for power devices - Part 1: Classification of defects
1 Scope
This document gives a classification of defects in as-grown 4H-SiC (Silicon Carbide) epitaxial layers. The defects are classified on the basis of their crystallographic structures and recognized by non-destructive detection methods including bright-field OM (optical microscopy), PL (photoluminescence), and XRT (X-ray topography) images.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
——IEC Electropedia: available at http://www.electropedia.org/
——ISO Online browsing platform: available at http://www.iso.org/obp
3.1
silicon carbide; SiC
semiconductor crystal composed of silicon and carbon, which exhibits a large number of polytypes such as 3C, 4H, and 6H
Note: A symbol like 4H gives the number of periodic stacking layers (2, 3, 4,…) and the crystal symmetry (H = hexagonal, C = cubic) of each polytype.
3.2
3C-SiC
SiC crystal with zinc blende structure, in which three Si-C layers are periodically arranged
along the <111 > direction
3.3
4H-SiC
SiC crystal showing a hexagonal symmetry, in which four Si-C layers are periodically arranged along the crystallographic c-axis
Note: The crystal structure of 4H-SiC is similar to wurtzite with a unit cell having four periodical occupied sites along the <0001> direction.
3.4
6H-SiC
SiC crystal showing a hexagonal symmetry, in which six Si-C layers are periodically arranged along the crystallographic c-axis
Note: The crystal structure of 6H-SiC is similar to wurtzite with a unit cell having six periodical occupied sites along the <0001> direction.
3.5
crystal plane
plane, usually denoted as (hkl), representing the intersection of a plane with the a-, b- and c-axes of the unit cell at distances of 1 /h, 1 /k and 1 /l, where h, k and l are integers
Note 1: The integers h, k and l are usually referred to as the Miller indices of a crystal plane.
Note 2: In 4H-SiC showing a hexagonal symmetry, four-digit indices are frequently used for planes (hkil).
[SOURCE: ISO 24173:2009, 3.2, modified - Note 2 has been entirely redrafted.]
3.6
crystal direction
direction, denoted as [uvw], representing a vector direction in multiples of the basis vectors describing the a-, b- and c-axes
Note 1: In 4H-SiC showing a hexagonal symmetry, four-digit indices [uvtw] are frequently used for crystal directions.
Note 2: Families of symmetrically equivalent directions are written by and for cubic and hexagonal symmetries, respectively.
[SOURCE: ISO 24173:2009, 3.3, modified - Note 1 and Note 2 have been added.]
3.7
polytypism
phenomenon where a material occurs in several structural modifications, each of which can be regarded as built up by stacking layers of identical structure and chemical composition
3.8
polytype
one of the modifications of monocrystalline material which shows polytypism
3.9
substrate
material on which homoepitaxial layer is deposited
3.10
homoepitaxial layer
thin monocrystalline film epitaxially-formed on a substrate of the same material and crystallographic orientation, inheriting the atomic order of the substrate
3.11
crystal
monocrystalline material
3.12
lattice site
arrangement position of the atoms in crystal
3.13
basal plane
plane perpendicular to the crystallographic c-axis in a hexagonal crystal
3.14
prism plane
plane parallel to the crystallographic c-axis in a hexagonal crystal
3.15
crystallographic c-axis
principal axis in a hexagonal crystal
3.16
defect
crystalline imperfection
Note 1: Defect of SiC homoepitaxial wafers including point defect, extended defects, surface defects, and others.
3.17
crystal defect
local alteration of crystal periodicity
Note: Crystal defect is generally classified into point and extended defects.
3.18
point defect
crystal defect that occurs at or around a single lattice site, such as a vacancy, interstitial, antisite, impurity and complex
3.19
vacancy
lattice site of a lack of atom in crystal
3.20
interstitial
atom that occupies a site in monocrystalline material, at which atoms usually do not exist
3.21
extended defect
crystal defect extended in space in one, two or three-dimension
3.22
dislocation
linear crystallographic defect in monocrystalline material
3.23
micropipe
hollow tube extending approximately normal to the basal plane
3.24
threading screw dislocation; TSD
screw dislocation penetrating through the crystal approximately normal to the basal plane
3.25
threading edge dislocation; TED
edge dislocation penetrating through the crystal approximately normal to the basal plane
3.26
basal plane dislocation; BPD
dislocation lying on the basal plane
