HPHT Single Crystal Diamond Seed Plates are used as substrates for homoepitaxial CVD diamond growth.
We supplies yellow and white HPHT diamond seed plates in standard sizes from 3 × 3 mm to 7 × 7 mm, with larger dimensions available subject to material availability. Standard thickness is 0.3 mm, while 0.2 mm, 0.5 mm, 0.8 mm and thicker plates can be provided on request.
HPHT diamond seed plates are widely used because they provide an accessible, mature and customizable single crystal diamond substrate for CVD homoepitaxial growth
Technical Specifications
| Specification | Value |
|---|---|
| Product name | HPHT Single Crystal Diamond Seed Plates |
| Material | HPHT single crystal diamond |
| Typical use | High-quality CVD diamond, electronic-grade CVD diamond, optical-grade CVD diamond |
| Standard size range | 3 × 3 × 0.3 mm to 7 × 7 × 0.3 mm, or larger size, or custom |
| Thickness | 0.3 mm standard; 0.2 mm, 0.5 mm, 0.8 mm, 1.0 mm+ available |
| Color options | Yellow HPHT diamond / White HPHT diamond |
| Crystal structure | Single crystal |
| Growth method | HPHT |
| Stress characteristic | Low-stress seed substrate |
| Shape | Square shape / Rectangular shape / As-grown shape |
| Surface finish | Double polished, Ra < 30 nm |
Ib & IIa Type Options
(Yellow & White HPHT Diamond Seed Plates)
Diamond Component supplies both yellow and white HPHT single crystal diamond plates for seed applications.
| Type | Description | Picture |
|---|---|---|
| Yellow HPHT diamond seed plate | Diamond type: Ib, with yellow color appearance | ![]() |
| White HPHT diamond seed plate | Diamond type: IIa, higher visual transparency / white appearance | ![]() |
Color is used as a selection reference and does not replace technical evaluation. For CVD growth projects, the final choice should be based on seed quality, stress condition, surface finish, crystal quality and growth requirements.
Shape Options
HPHT Single Crystal Diamond Seed Plates are available in two main shape options: as-grown shape and square / rectangular laser-cut shape. The best option depends on the customer's CVD growth process, reactor design, seed mounting method and crystal orientation requirements.
| Shape Option | Description | Picture |
|---|---|---|
| As-Grown Shape | The seed plate keeps its original as-grown outline. The edges are not laser-cut, and the natural crystal edges are retained. Shape may vary from piece to piece. | ![]() |
| Square or Rectangle Shape | Four edges are laser-cut to form a regular square or rectangular plate with four right-angle corners. Edge crystal orientation can be specified by the customer. | ![]() |
HPHT Seed Plates vs CVD Seed Plates
| Item | HPHT Diamond Seed Plates | CVD Diamond Seed Plates |
|---|---|---|
| Materials type | HPHT, Ib &IIa type | CVD, IIa type |
| Crystal structure | Single crystal | Single crystal |
| Stress level | Low stress of selected seeds | May have higher residual stress depending on growth condition |
| Main Features | Small size. Provide a stable single crystal diamond template to allow the CVD layer to continue growing along the existing lattice. | Large size up to 30mm |
| Picture (Stress) | ![]() |
![]() |
HPHT seed plates are often selected when the customer needs a low-stress starting substrate for growing high-quality CVD diamond layers.
Request a Quote
HPHT diamond seed plates are supplied according to size, thickness, color, surface finish, crystal quality and application requirements. Please submit your CVD growth requirements for quotation.
Please include:
1) Required size and thickness
2) Yellow or white HPHT diamond preference
3) Shape preference
4) Quantity
5) Orientation requirement, if any
6) Target delivery date
Important Notes
This product is supplied as an industrial functional diamond seed material. It is not a jewelry diamond, gemstone, loose diamond or decorative lab-grown diamond.
Standard dimensions and custom sizes are subject to material availability, yield and technical feasibility. For electronic-grade CVD growth, customers should confirm final suitability through their own growth process and qualification tests.




