4H Silicon Carbide Vs 6H Silicon Carbide

4H-SiC is an increasingly popular polytype of silicon carbide. Due to its wide bandgap and excellent thermal, electrical, and mechanical properties, it makes an ideal material for power electronics applications.

We investigated the elastic deformation and cracking behavior of a single crystal 4H-SiC pillar specimen with [0001] orientation by performing four times loading-unloading compression strain tests with four loading/unloading cycles for compression strain testing.


Silicon carbide (commonly referred to as “carborundum” or the “crown jewel”) is the hardest naturally occurring material on Earth. Comprised of silicon and carbon elements, silicon carbide naturally occurs as moissanite gems in nature; mass production began in 1893 for use as an abrasive and cutting tool – typically found as small grains as an abrasive or large single crystals cut into gemstones – or cut directly from large crystals for cutting tool use. Its properties make it ideal for electrical applications due to its durability against high temperatures and voltages – making silicon carbide an excellent material choice when considering electrical applications.

4H-SiC’s resistance to high voltages and temperatures makes it a useful material for producing radio frequency (RF) devices such as power amplifiers in cellular base stations as well as sensors for aerospace and automotive use. Furthermore, its excellent thermal conductivity provides efficient heat dissipation from electronic devices.

Instrumented nanoindentation can be a useful method of gauging the mechanical properties of 4H-SiC materials, including hardness and elastic modulus. However, its geometry has been known to influence hardness values at low load conditions – potentially yielding false readings with severe cracking observed at corners of indentation imprints that result from it.


Silicon carbide’s rigidity is one of its hallmark characteristics, making it an invaluable material for power electronics applications and telescope mirrors alike. Furthermore, it resists high temperatures and electric fields without losing its integrity – ideal qualities when considering thermal expansion during use in astronomical telescopes.

Silicon carbide’s wide bandgap makes it suitable for high voltage and frequency applications, but choosing the appropriate polytype for each application is critical; different atomic arrangements influence physical and electrical properties of materials, with 4H and 6H being two popular choices among silicon carbide polytypes that possess similar properties but differing crystalline structures and atomic arrangements.

4H-SiC’s atomic arrangement can have a substantial impact on its brittle deformation performance. Atomic configurations on (12-10) and (0001) planes produce different properties such as hardness and elastic modulus that manifest themselves through load-versus-indentation-depth curves; additionally, basal indentations have higher elastic modulus than prismatic indentions.

[0001]-oriented single-crystalline 4H-SiC nanopillars present an exciting opportunity for engineering electron mobility and bandgap structure through nanomechanical straining, providing the means to develop materials with increased electron mobility and low loss power electronic devices as well as providing a platform for creating microelectromechanical systems (MEMS) or flexible devices.


Silicon carbide is an impressive material with superior mechanical, electrical and optical properties. Highly durable and resisting thermal shocks, its hardness and rigidity make it suitable for aerospace applications as well as mechanical components; with low thermal expansion rates and excellent thermal conductivity properties making it suitable for power electronics as well. Silicon carbide forms an integral component in many cutting-edge electronic devices today.

Silicon carbide’s crystal structure determines its properties and performance. It comes in different polytypes, such as 6H and 4H. Each differs in its crystalline structure, lattice constants, physical properties and distribution of carbon interstitials and vacancies – such as how fast injection rates of interstitials onto an oxidizing surface occur, their diffusivity from there into bulk silicon carbide materials can influence recombination of vacancies within silicon carbide.

SiC films with low concentrations of boron impurities exhibit high isotropic thermal conductivities, known as thermal conductivity coefficients. 3C-SiC excels with isotropic thermal conductivity coefficients exceeding 500 W m-1 K-1; second only to single crystal diamond. Furthermore, this value significantly outshines other large-crystal semiconductors like 4H-SiC and AlN as ion implanted materials, but lower than 6H-SiC due to lack of carbon vacancies within its structure.

Electrical Conductivity

Silicon carbide is an extremely versatile semiconductor material with many applications across many fields of electronics and beyond. With its thermal conductivity and wide bandgap characteristics, silicon carbide makes an excellent material choice for high-power and high-frequency electronics devices as well as electric vehicles and renewable energy systems. There are various polytypes of silicon carbide available with each offering its own strengths and weaknesses; understanding these differences between 4H-SiC and 6H-SiC can help manufacturers choose the ideal material for specific projects.

Silicon carbide’s crystal structure is crucial to its electrical and thermal properties. Composed of double layers of carbon atoms arranged in either an ABCB or ABBA stacking sequence, its crystal has different symmetry and lattice constants depending on which stacking sequence it uses; 4H SiC crystals feature hexagonal shapes while 6H-SiC exhibit cubic forms.

H+ ions implanted into 4H-SiC can dislocate and displace its Si and C atoms, creating point defects which trap electrons. X-ray diffraction can detect these point defects that trap electrons; photoluminescence spectroscopy measures these defects for characterizing ion implantation process while rocking curves measure strain caused by this implanting process; even though its mechanical strength makes this material highly resilient against stress and strain, even with regards to 4H-SiC still being susceptible against stress and strain due to being affected by external influences.

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