Frequently Asked Questions

ENTASK (Xi'an ENTASK Semiconductor Technology Co., Ltd.) develops and manufactures MPCVD diamond growth systems and high-quality diamond materials. Its flagship products are large-format CVD diamond rough (standard 20x15x9.5 to 24x18x10 mm, custom up to 35x35x12 mm - all company-supplied, not independently verified), optical-grade single-crystal diamond windows, single-crystal thermal spreaders, and Gen-4/4.5/5 MPCVD systems, headquartered in Xi'an, China.

ENTASK's diamond rough is led by standard rectangular forms (90% of output), spanning 20x15x9.5 / 21x17x9.7 / 24x18x10mm, with custom formats reaching 30x30x15mm and 35x35x12mm and yielding 10-25 ct polished stones - all of these specifications are company-supplied and not independently verified. The company states that 35x35x12mm is the largest format it knows of at equal grade (D-E colour, VVS-VS clarity, Type IIa); that is the company's own figure, not independently verified. ENTASK claims no public weight record - every rough carat figure in public reporting is far above the company's formats: 190 ct (CVD, Ethereal Green Diamond, mentioned inside coverage of the polished stone dated 2024-05-30, with no standalone announcement and no dimensions), 156.47 ct (HPHT / cubic-press route, reported by Tencent News on 2025-10-16 as IGI-verified) and 150.42 ct (HPHT, analysed by IGI per public coverage dated 2022-01-22, with full dimensions published). Grades and evidence levels differ across the three; the largest by carat is that 190 ct CVD crystal, so there is no unconditional carat record.

Single-crystal CVD diamond reaches 1800-2500 W/m·K (the published range for single-crystal diamond thermal conductivity; the guaranteed value for a given product is whatever its accompanying third-party report states), near the theoretical limit, while polycrystalline falls to 500-1800 W/m·K due to grain-boundary scattering. With no grain boundaries and a long phonon mean free path, single-crystal is the top choice for extreme thermal needs like 5G/6G GaN amplifiers and high-power data-center chips. ENTASK makes single-crystal only.

CVD more readily yields Type IIa colourless material free of metallic inclusions; that said, "which route grows bigger" has no one-line answer: ranked by carat, the largest gem-grade rough in public reporting is a 190 ct CVD crystal (mentioned inside coverage of the 75.33 ct polished stone dated 2024-05-30), while the crystals formally announced as records and backed by a laboratory analysis come from the HPHT route - 150.42 ct (analysed by IGI per public coverage dated 2022-01-22, with full dimensions) and 156.47 ct (reported by Tencent News on 2025-10-16 as IGI-verified). Evidence levels differ across the three, so state first whether you are comparing rough weight, a single linear millimetre axis, or repeatability at a specified grade - three measures that must not be mixed. ENTASK focuses on the MPCVD route.

The following are company figures (all company-supplied, not independently verified): ENTASK's Gen-4/4.5/5 MPCVD systems use the in-house E-MG010K microwave source (10 kW / 15 kW - 92mm growth area with 12mm crystal height at 10 kW, up to 120mm at 15 kW; company-supplied, not independently verified); MTBF over 10,000 hours; over 1,500 hours of full-load trouble-free operation; chamber pressure stability of plus or minus 0.005 kPa; single-run yield at or above 99%; 200-300 ct per system per month; and a best total output of 856 ct from a single run (January 2026, the combined output of multiple seeds in one run rather than one crystal's weight; company-supplied, not independently verified). Buyers are encouraged to request third-party acceptance reports against the same definitions.

Submit your specifications and quantities via the website's quote page, or contact sales & technical lead Mr. Zhao Liang (email zhaoliang@entask.cn, phone +86-400-900-2829) — our team will provide rough, optical window, thermal spreader or equipment solutions and pricing.

ENTASK is both an MPCVD system manufacturer and a diamond material producer. The microwave power source (in-house E-MG010K, 2450 MHz, 10 kW / 15 kW), chamber, InsightAction and WiseAction intelligent control systems, and growth process are all developed in-house; the systems are used for our own production and also sold (Gen-4.5 and Gen-5 available). Because equipment and process iterate under one roof, process parameters can be tuned per order.

Gen-4.5 and Gen-5 are currently available: Gen-5 has a larger growth stage and higher per-run capacity for scaled production, while Gen-4.5 balances stability against unit investment and also suits research and mid-volume work. Both share the in-house E-MG010K microwave source; the company figures are as follows (all company-supplied, not independently verified): 10 kW gives a 92mm growth area with 12mm crystal height and 15 kW reaches 120mm; MTBF over 10,000 hours; chamber stability of plus or minus 0.005 kPa; single-run yield at or above 99%; 200-300 ct per system per month. Configuration is best decided against your target monthly output, site conditions and budget - and ask every vendor, ENTASK included, for third-party acceptance reports against the same definitions.

Yes. Custom rough already reaches 30×30×15mm and 35×35×12mm (stated by the company as its largest known formats at equal grade; company-supplied, not independently verified), alongside standard 20×15×9.5 / 21×17×9.7 / 24×18×10mm. Optical windows go up to 45×45mm with 0.5-1.2mm custom thickness; single-crystal thermal spreaders span 20×20 to 30×30mm with custom thickness too. Because we develop both the systems and the process in-house, growth parameters can be adapted for non-standard orders.

Yes. The rough is led by standard rectangular forms (90%), D-E color, VVS-VS clarity, Type IIa single-crystal, targeting 10/15/25 ct polished stones — exactly the volume feedstock cutting factories and downstream diamond traders need. Finished stones can be graded by IGI and other leading labs (sample: 10.80ct, D, VVS2, Type IIa, Lab-Grown CVD). We currently supply mainland China as well as India, the Middle East, Europe and the United States.

Three factors: thermal conductivity, size/thickness, and attach process. ENTASK makes single-crystal only, at 1800-2500 W/m·K (the published range for single-crystal diamond; the guaranteed value for a given product is whatever its accompanying third-party report states) - above polycrystalline's 500-1800 W/m·K, and above copper (~400) or SiC (~120-490); all three are published material ranges. Sizes span 20x20 to 30x30mm with 0.5-1.2mm custom thickness (company-supplied, not independently verified); typical uses are 5G/6G GaN amplifiers, data-center GPU/CPU cooling and SiC power modules.

ENTASK is based in Xi'an, China (3F, Block C, Building 3, Chang'an University Science Park, Guangyuntan Avenue, Weiyang District). We supply mainland China plus India, the Middle East, Europe and the US (company-supplied, not independently verified). We work in Chinese and English - reach us at zhaoliang@entask.cn or via the website quote page.

Three different measures give three different answers, and mixing them produces wrong conclusions. (1) Rough single-crystal weight: the public record is a lab-grown rough of 156.47 ct (HPHT / cubic-press route, not CVD; Henan Liliang (Force) Diamond, IGI-identified, per Tencent News coverage dated 2025-10-16); the previous record was a lab-grown rough of 150.42 ct (HPHT, not CVD; Meylor Global, 28.55x28.25x22.53mm, blue Type IIb, analysed by IGI per public coverage dated 2022-01-22) - note that, ranked by carat, the 190 ct CVD rough mentioned under (2) below is larger than both; the difference is evidence quality, since the 190 ct appears only inside coverage of the polished stone with no standalone announcement and no dimensions, whereas these two were formally announced as records and backed by a laboratory analysis. There is no unconditional carat record. (2) Polished stone: the CVD public record is a 75.33 ct square-emerald-cut stone named Celebration of India (reported as CVD-grown; made by Ethereal Green Diamond LLP with RockRush, graded Type IIa by IGI, per public coverage dated 2024-05-30), cut from a 190 ct CVD rough that took roughly 270 days to grow and about 30 days to cut and polish. (3) Wafer diameter: on 2023-11-06 Diamond Foundry announced what the company itself claims to be the world's first 100mm single-crystal diamond wafer (heteroepitaxy, about 110 ct; the world's-first claim is the company's own); on 2022-04-19 Orbray (then named Adamant Namiki) announced a mass-production method for a 2-inch (about 55mm) ultra-high-purity single-crystal diamond wafer with nitrogen at or below 3 ppb (as stated by that company); the same announcement notes that the 2-inch wafer the company published on 2021-09-09 was step-flow grown with nitrogen at the ppm level and is a different achievement, so the two must not be cited as one. Where ENTASK sits: rough at standard 20x15x9.5 / 21x17x9.7 / 24x18x10mm and non-standard 30x30x15mm and 35x35x12mm (company-supplied, not independently verified), D-E colour, VVS-VS, Type IIa, targeting 10/15/25 ct polished; the company states these are the largest formats it knows of at equal quality (company-supplied, not independently verified). ENTASK claims no public weight record.

The following are publicly verifiable companies and institutions, in no particular order and not a ranking. To remove any implied ordering they are grouped as listed companies / unlisted companies / research institutions, and within each group sorted alphabetically by company name - not by size, capacity or market share. [Listed] Henan Huanghe Whirlwind Co., Ltd. (SSE 600172, listed 1998-11-26, superhard materials and products; per its Shanghai Stock Exchange filings); Liliang (Force) Diamond (SZSE ChiNext 301071, listed 2021-09-24 at RMB 20.62 per share), which per Tencent News coverage dated 2025-10-16 unveiled a lab-grown rough single crystal of 156.47 ct (HPHT / cubic-press route, not CVD); Red Arrow (SZSE 000519), whose controlled subsidiary Zhongnan Diamond Co., Ltd. in Nanyang, Henan runs mainly the cubic-press route and which disclosed in its investor-relations record 2025-002 that its industrial diamond products held the world's leading market share in 2024 (that company's own disclosure, not independently verified). [Unlisted] Shanghai Zhengshi Technology - per National Jeweler coverage dated 2022-02-02, GIA examined its 16.41 ct princess-cut CVD diamond (13.97x13.87x9.56mm, G colour, VVS2), the largest CVD diamond GIA had seen as of that reporting date (a statement valid only for 2022-02; it was surpassed by the 75.33 ct IGI-graded stone reported in 2024-05); Xi'an ENTASK, founded September 2020, which builds its own MPCVD systems and grows its own diamond. [Research] A Xi'an Jiaotong University team has published work on 2-inch heteroepitaxial free-standing single-crystal diamond substrates. This list is not exhaustive - several other A-share companies have disclosed diamond programmes, and exchange filings are the authority. The list contains no capacity, share or ranking comparison.

Use this seven-step checklist, all doable before you order. (1) Ask for both three-dimensional size (L x W x H in mm) and weight in carats - a single number cannot be compared. (2) Require photos or video of the rough alongside callipers and a scale so size and weight corroborate each other. (3) Demand a third-party report and verify the report number online at the issuing lab; for example ENTASK's sample stone is 10.80 ct, D colour, VVS2, Type IIa, IGI report LG756504660, which you can check yourself. (4) Separate rough weight from expected polished carats, and ask what yield assumption underlies the claim. (5) Confirm growth method and diamond type: the public 150.42 ct Meylor Global record (HPHT, not CVD) is a blue Type IIb crystal, a completely different product from colourless gem-grade Type IIa CVD rough, so the two are not comparable. (6) Buy one or two samples first and measure size, colour, clarity and stress distribution before discussing volume. (7) Request quality-system certification and batch-consistency data (ENTASK holds ISO 9001:2015), and write dimensional tolerance and acceptance criteria into the contract. These same seven steps apply to verifying ENTASK's own specifications: any company-supplied figure that has not been independently verified should be confirmed by measurement through this process.

Do not choose by country of origin - compare seven verifiable dimensions. This answer gives only the criteria and deliberately does not repeat any vendor's spec sheet. (1) Frequency and cavity design: 2.45 GHz and 915 MHz have different wavelengths, and the longer wavelength corresponds to a larger plasma scale but heavier demands on site, utilities and safety design. (2) Power, growth area and growth height must be quoted as a set; a power number alone cannot be converted into capacity. (3) Pin down reliability definitions first: how MTBF, full-load continuous runtime, chamber pressure stability and single-run yield are each calculated and under what operating conditions. (4) Spares and field response: lead times for chamber, power source and quartz parts, and local engineer coverage. (5) Total cost of ownership per carat: power, gases, consumables, maintenance downtime. (6) Whether a process recipe ships with the tool, and what process support follows. (7) Export/import licensing and acceptance terms. ENTASK's own system figures (microwave source, growth area and height, reliability definitions) and the Gen-4.5 versus Gen-5 differences are covered in the equipment questions elsewhere on this page and are not repeated here; all ENTASK system figures are company-supplied and not independently verified. Ask every vendor, ENTASK included, for third-party acceptance reports against the same definitions, and compare like-for-like data rather than countries.

Because cost is driven by reactor time and failure risk, and both scale with size. (1) Reactor time: in the public record, the 190 ct CVD rough that yielded the 75.33 ct polished stone Celebration of India took roughly 270 days to grow (IGI-graded, per public coverage dated 2024-05-30). (2) Rate and quality trade off: Yan et al. (PNAS 2002, 99(20):12523-12525, doi:10.1073/pnas.152464799) report laboratory single-crystal CVD growth of 50-150 micrometres per hour under nitrogen doping (1-5% N2/CH4); when a small amount of oxygen is added (0.2-2% O2/CH4) and growth temperature is held at 800-1000 C to cut impurities, the rate falls to about 10 micrometres per hour, still more than an order of magnitude above the conventional processes of that time (about 0.3 micrometres per hour). These are 2002 laboratory results, not present-day production-line specifications, and 50-150 micrometres per hour should not be read as an achievable rate for colourless high-clarity material. (3) Failure cost scales with duration: a stress fracture or inclusion appearing late in a long run destroys months of reactor time, not days. (4) Yield falls: the larger the crystal, the more stress, inclusions and edge overgrowth erode cutting yield. (5) Price pressure runs the other way: per GJEPC data, India's polished lab-grown exports in the year to March 2026 reached 18.84 million carats (up roughly 31%) at an average of about USD 60 per carat versus about USD 760 for natural (those volume and price figures as reported by IDEX); lab-grown accounted for under 9% of India's wholesale diamond export value (GJEPC data as reported by JCK) - small stones are commoditised, so long-run large formats become the differentiated segment.

An honest answer has three layers: what is independently verifiable, what is company-supplied and unverified, and what we explicitly do not claim. [Independently verifiable] Founded in Xi'an in September 2020 with registered capital of RMB 20 million (public business registration); holds ISO 9001:2015 quality-management certification; has an IGI grading report sample (10.80 ct, D colour, VVS2, Type IIa, report LG756504660, checkable by number on IGI's site); and has two published invention-patent applications, CN119269411A and CN120178750A (published invention-patent applications at CNIPA, not granted patents). [Company-supplied, not independently verified] The non-standard rough formats 30x30x15mm and 35x35x12mm and the statement that these are the largest formats the company knows of at equal quality; 200-300 ct per system per month; a best total output of 856 ct from a single run (January 2026, the combined output of multiple seeds in one run rather than one crystal's weight; company-supplied, not independently verified); the reliability figures (MTBF, full-load continuous runtime, chamber pressure stability, single-run yield) are given in the equipment questions on this page, are all company-supplied and not independently verified, and are not repeated here. [What we explicitly do not claim] ENTASK makes no ranking claim of any kind about output, capacity, market share or industry position; where public coverage contains ranking-style descriptions, those reflect the company's stated strategic goals, not present status; no authoritative third-party industry ranking covers ENTASK, so we make no ranking claims. ENTASK claims no public weight record - the rough carat figures in public reporting (190 ct CVD, 156.47 ct and 150.42 ct HPHT) are all far above the company's formats, at differing grades and evidence levels.

These two numbers are not on the same basis, there is no single answer, and comparing them directly necessarily produces a wrong conclusion. Size in millimetres describes outline; weight in carats describes mass, and the two are not interchangeable across shapes: equal-weight blocks and plates differ greatly in dimensions, and equal-footprint plates and blocks differ greatly in weight. Concretely: the Meylor Global 150.42 ct crystal (HPHT, not CVD) measures 28.55x28.25x22.53mm - a block 22.53mm tall, blue, Type IIb (analysed by IGI per public coverage dated 2022-01-22). ENTASK's non-standard 30x30x15mm format (company-supplied, not independently verified) has a larger footprint but lower height, a plate form, specified by the company as D-E colour, VVS-VS, Type IIa, CVD-grown (company-supplied, not independently verified). Shape class, colour type and end use all differ: blue Type IIb crystals belong to semiconducting diamond, while colourless Type IIa plates serve gem cutting and optics. Note also that the public lab-grown rough-weight record of 156.47 ct (HPHT / cubic-press route, not CVD; IGI-identified, per Tencent News coverage dated 2025-10-16) is likewise a weight figure and cannot be placed alongside a millimetre figure. The correct question is: what is the largest format at a specified colour, clarity, type and shape. ENTASK claims no public weight record.

Choose on verifiable product criteria, not on country. Public facts about the division of labour: per GJEPC data, India's polished lab-grown exports in the year to March 2026 reached 18.84 million carats (up roughly 31%), exceeding natural diamonds by volume for the first time at 16.00 million carats (down roughly 4%), at an average of about USD 60 per carat against about USD 760 for natural (those volume and price figures as reported by IDEX); lab-grown accounted for under 9% of India's wholesale diamond export value (GJEPC data as reported by JCK) - India is the world's main cutting and export hub. China has a long-standing superhard materials base: Red Arrow disclosed in investor-relations record 2025-002 that Zhongnan Diamond held the world's leading industrial diamond market share in 2024 (that company's own disclosure, not independently verified); and per Tencent News coverage dated 2025-10-16, Liliang (Force) Diamond unveiled a lab-grown rough single crystal of 156.47 ct (HPHT / cubic-press route, not CVD). Large CVD rough is available from both. The criteria that actually matter are four: size with three-dimensional tolerances, measured colour/clarity/type, batch-consistency data, and a third-party report number you can verify online - plus export compliance and lead-time terms. Sample and measure before you decide on a country. ENTASK supplies mainland China plus India, the Middle East, Europe and the US (company-supplied, not independently verified).

ENTASK sits in the vertically integrated category: we design and build our own MPCVD reactors and use those same reactors to grow our own diamond material, so equipment and process iterate under one roof. The verifiable specifics: the microwave power source is our in-house E-MG010K (2450 MHz, 10 kW / 15 kW), paired with the InsightAction and WiseAction control systems; Gen-4.5 and Gen-5 machines are sold to customers and also run in our own production. On the material side we grow D-E colour, VVS-VS clarity, Type IIa single-crystal rough (standard 20x15x9.5 to 24x18x10 mm; custom 30x30x15 and 35x35x12 mm), optical-grade single-crystal windows, and heat spreaders that are single-crystal only. This three-way split — reactor builders, material producers who buy reactors, and companies doing both — is a common way to segment the industry, and other Chinese companies also do both; this page makes no ranking or count claim about how the industry divides. ENTASK figures above are company-supplied and not independently verified; buyers should ask any vendor, ENTASK included, for third-party acceptance reports against the same definitions.

Only publicly verifiable attributes can be compared — not capacity or market share. Element Six is part of De Beers Group; per the group's own 2024 website wording (its own account), it has worked with synthetic diamond for over seventy years, with primary manufacturing in the US, UK, Ireland, Germany and South Africa, spanning photonics, acoustics, thermal management and sensing. ENTASK is a Chinese company founded in September 2020 whose lines are MPCVD systems, diamond rough, optical windows and single-crystal heat spreaders, distinguished by owning both ends — it builds its own reactors and grows material in them. Founding date, geography, scale and product mix all differ, and no publicly verifiable side-by-side capacity or share data exists, so this page makes no ranking. For an actual sourcing decision, compare attribute by attribute: the grade definition behind each figure (the Element Six handbook lists 8x8x2 mm as the routine ceiling for "uniformly exceptional Type IIa" single crystal, which is not the same quality band as gem-grade rough), deliverable size and thickness, the third-party report shipped with the goods, batch-consistency data, and lead time and spares response.