CVD SiC Coated Graphite RTP Tray

RTP systems really put wafer support trays through the wringer. Every cycle, the tray gets heated up in a hurry and then cooled down just as fast – and that happens thousands of times over its lifetime. If the material or the manufacturing process isn't carefully controlled, that repeated thermal shock can slowly cause the tray to warp or lose its shape.

Our approach isn't just about surviving high temperatures – it's about making sure wafers stay firmly supported and evenly heated, cycle after cycle.

Why SGL6510 Graphite?

So why do we pick SGL6510? Because the substrate is the backbone of the whole tray. SGL6510 is an isostatic graphite with a remarkably uniform structure, high thermal conductivity, and low thermal expansion – all of which help reduce internal stress and keep the tray dimensionally stable over time. That's especially important for thin trays that go through a lot of temperature cycling.

After we machine the graphite to the required shape, we apply a dense CVD SiC coating. This coating protects the surface from oxidation, corrosion, and wear, and it also keeps particle generation to a minimum.

Flatness Matters More Than Temperature

Actually, most people assume the big challenge is whether the tray can handle 700°C. But that's not really the issue – the real headache is deformation. A thin graphite tray can warp during machining, during coating, or simply from repeated heating and cooling. Even a tiny change in shape can affect how well the wafer sits and how evenly the heat spreads.

That's why flatness control is one of our top priorities throughout manufacturing. We use high-quality SGL6510 graphite with a uniform internal structure, we keep machining tolerances tight before coating, we use a low-stress CVD SiC process, and we check flatness after every major production stage. The result: most of our trays achieve flatness ≤0.50 mm, and many come out even flatter.

Material Performance

The CVD SiC coating isn't just a thin shell – it forms a dense, hard barrier that really extends the life of the graphite underneath. In real-world use, that translates to fewer particles, excellent resistance to oxidation and corrosion, and good thermal shock resistance. These trays are built to last in semiconductor cleanrooms.

Our standard coating thickness is 100 ± 20 μm, but we can adjust that if your application calls for something else.

Why Choose Semixlab?

Making a reliable RTP tray is about more than just coating graphite with SiC. When the tray is thin, every detail counts – machining precision, coating stress, final flatness. We've been working with precision graphite and CVD SiC coatings for years, so we understand how to balance these factors. The end result is a tray that holds its geometry, stays clean, and gives you a long service life in production.

● Product: CVD SiC Coated Graphite RTP Tray

● Base Material: SGL6510 Isostatic Graphite

● Surface Coating: CVD Silicon Carbide (SiC)

● Coating Thickness: 100 ± 20 μm (customizable)

● Max Continuous Service Temperature: up to 1400°C

● Typical Process Temperature: around 700°C

● Flatness: ≤0.20 mm (design-dependent)

● Custom Design: available

You'll find these trays in a variety of semiconductor processes – RTP, RTA, general high-temperature wafer support, and cleanroom fabrication. Their main job is simple: hold the wafer securely and transfer heat consistently throughout the thermal cycle.

1. Why does flatness matter so much?

Because the tray directly supports the wafer during rapid heating and cooling. If it warps even a little, the wafer might not sit evenly, which can throw off heat distribution and process repeatability.

2. Can the tray run continuously at 700°C?

Yes – 700°C is well within its comfort zone. The tray is rated for continuous use up to about 1400°C, so 700°C is no problem.

3. What coating thickness do you offer?

Our standard is 100 ± 20 μm, but we can tailor it if your application needs a different thickness.

4. Do you make custom RTP trays?

Absolutely. We can work from your drawings to produce trays with specific dimensions, coating thickness, flatness requirements, and any other specs you need.