A Silicon Carbide Wafer is a Critical Component in the Power Devices That Drive the World’s Newest Technologies

Silicon carbide wafers are key components in power devices that drive cutting-edge technologies worldwide. Rising demand and efforts to bring power device performance closer in line with that of traditional silicon-based substrates necessitate innovative solutions.

Originating as an industrial abrasive material since 1893 and found only rarely as moissanite jewels, SiC is hard and brittle, necessitating manufacturers to adopt unique procedures in order to successfully process this material.

Electrical and thermal properties

Silicon carbide is an extremely versatile material, ideal for use as a semiconductor substrate. Its physical hardness (second only to diamond), stability under high temperatures and current, resistance to chemical attack, durability and chemical ingress resistance all make it highly appealing. Non-electronic uses include bulletproof vest plates. With higher voltage threshold levels than silicon it also makes an excellent material choice for power electronics applications like power converters or inverters.

Due to its wide bandgap, sapphire makes an excellent material choice for energy-efficient electronic devices. It can operate at higher temperatures and voltage levels than conventional silicon-based devices while simultaneously producing more power per unit volume. Plus, due to its low coefficient of thermal expansion (CTE), no size changes when heated or cooled down so smaller devices can fit more seamlessly within smaller designs, providing faster electrical performance.

Chemical Mechanical Polishing (CMP), the final major process step of wafer production, removes small amounts of material from the surface to prepare it for epitaxial growth. CMP is an essential step which must be executed perfectly to achieve maximum yield and quality; any failure would compromise device performance and yield. Successful CMP requires using specialized polishing slurry combined with polyurethane or urea impregnated felt polishing pads that effectively remove material without altering wafer shape;

Applications

Silicon carbide (SiC) is widely utilized across electronics applications, from power semiconductors to thermal conductivity sensors. Due to its superior physical properties and increased efficiency over silicon-based counterparts, SiC provides higher breakdown voltages and lower turn-on resistance than silicon alternatives – even eliminating heat sinks in many designs!

SiC’s increase in performance is made possible due to the wide gap between its energy levels – commonly referred to as its bandgap – and valence and conduction bands, known as its bandgap. While traditional silicon substrates typically possess only small gaps, allowing electrons more freely move between these bands – leading to significant power density gains as well as higher operating temperatures for enhanced device reliability.

As Moore’s Law nears its limits, demand for more efficient power semiconductors has become ever more pressing. This trend is driving silicon carbide (SiC) technology forward in various industries including photovoltaic and rail transit applications.

Producing sophisticated power semiconductors involves an intricate supply chain. SiC wafer costs make up a substantial percentage of total component prices and their quality plays an essential part in its final performance. Pureon provides advanced wafer consumables, so its polishing and surface laboratories have the capabilities of evaluating surface and polish roughness measurements on SiC substrates in order to shorten development cycle times while providing customers with representative data to reduce risk when testing new products.

Pureon’s wafer production solutions

Silicon carbide wafer production is essential to advancements in electric car, 5G and IOT technologies. These devices rely on high-performance semiconductors with excellent surface qualities; such perfection allows for smooth transmission, abrasion resistance and prevents bipolar degradation that is limited by planar dislocation density restrictions. All critical process steps must be performed precisely and reliably so as to achieve such flawless surfaces.

Successfully cutting high-quality blanks at the wire saw step is essential to the production of SiC wafers. Achieve upstream improvements in wafer shape may prove challenging, and its success depends on factors like polishing pad selection, slurry formulation and processing parameters as well as machine type. Polishing slurry formulation and polishing pads play a decisive role in shaping final wafer quality.

Pureon’s diamond-based slurries were specifically developed with this application in mind, using proprietary chemistry and diamond categories for lot-to-lot consistency across customer sites. When combined with an optimal polishing pad, these products can deliver outstanding stock removal rates while producing remarkable surface qualities on silicon carbide wafers.

Chemical Mechanical Polishing (CMP), is one of the primary processes involved in silicon carbide wafer production. CMP uses a hard polyurethane polishing pad with finely dispersed alumina or silica abrasive particles for removal of residue from ingot-slicing, grinding and lapping processes to produce highly reflective surfaces free from scratches or damage for epitaxial growth and device fabrication.

Manufacturing

Silicon has long been the go-to material in the semiconductor industry, with wafers composed of this element forming the basis for most devices. But as Moore’s Law nears its limit, silicon carbide (SiC) may soon emerge as a viable replacement material.

SiC is distinguished by its ability to withstand high temperatures and voltages, switch on/off times ten times faster than silicon and its lower coefficient of thermal expansion, resisting changes caused by temperature fluctuations. Its unique properties enable devices made out of SiC to be made on smaller wafers for manufacturing purposes.

Manufacturers must first overcome several key steps when manufacturing SiC wafers to gain these advantages. The manufacturing process begins by creating a boule (resembling a hockey puck and grown for weeks in ovens half as hot as the sun) then cutting into wafers using a precision saw before going through several chemical and mechanical processes to transform them.

Chemical mechanical polishing (CMP), which prepares substrate surfaces for epitaxial growth while leaving no or minimal changes to their shape, is one of the key steps in manufacturing SiC wafers at such high cost. Although difficult, chipmakers are striving to optimize CMP processes by increasing yield while decreasing manufacturing costs per wafer.