Articles
Gallium Nitride (GaN) Substrates
Semiconductor epitaxy is best performed on native substrates in order to minimize interface effects and defect formation. Gallium nitride epitaxy on Kyma GaN substrates greatly improves a number of important device properties of subsequent GaN epitaxy when compared with heteroepitaxial GaN on SiC, sapphire, or silicon.
| GaN on Bulk GaN | GaN on SiC | GaN on sapphire | GaN on Silicon | |
|---|---|---|---|---|
| Lattice Constant Mismatch | 0% | 3.5% mismatch | 14% mismatch | 17% mismatch |
| Dislocation Density | 104 - 106 / cm2 | 1 x 109 / cm2 | 5 x 109 / cm2 | 1 x 1011 / cm2 |
| Thermal Conductivity | 2.5 W/cm-k | 1.3 W/cm-k | 1.2 W/cm-k | 1.0 W/cm-k |
Kyma's high purity GaN substrate allows GaN-based device manufacturers to eliminate interlayers, processing steps, and improve device quality over those grown on any other substrate. Detailed product descriptions and specification sheets are listed below:
| n-type c-plane Bulk GaN (00.2) (Specification sheet) | ||||
|---|---|---|---|---|
| Grade | Macro Defects | Substrate Diameter | Part Number | |
| Laser | <1/cm2 | 10x10mm | G.10.N.A | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.N.A | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.N.A | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| LED | <5/cm2 | 10x10mm | G.10.N.B | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.N.B | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.N.B | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Research | <10/cm2 | 10x10mm | G.10.N.C | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.N.C | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.N.C | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Rider | >10/cm2 | 10x10mm | G.10.N.D | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.N.D | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.N.D | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Custom | Alternate polish: | single side, double side optical, double side epi-ready, N-face epi-ready only | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | |
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| Semi-insulating c-plane Bulk GaN (00.2) (Specification sheet) | ||||
|---|---|---|---|---|
| Grade | Macro Defects | Substrate Diameter | Part Number | |
| Production | <1/cm2 | 10x10mm | G.10.SE.A | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.SE.A | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.SE.A | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Research | <5/cm2 | 10x10mm | G.10.SE.B | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.SE.B | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.SE.B | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Test | >10/cm2 | 10x10mm | G.10.SE.C | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.SE.C | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.SE.C | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Rider | >10/cm2 | 10x10mm | G.10.SE.D | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| 18x18mm | G.18.SE.D | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| 30mm round | G.30.SE.D | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Custom | Alternate polish: | single side, double side optical, double side epi-ready, N-face epi-ready only | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | |
| Don’t see what you need? This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||||
| Non-polar and semi-polar bulk GaN (Specification sheet) | |||||
|---|---|---|---|---|---|
| Grade | Macro Defects | Substrate Diameter | Planes Available | Part Number | |
| Laser | <1/cm2 | 5x10mm | a (11.0), m (10.0), (11.2), (10.3), (10.1), and (20.1) | A.5.N, M.5.N, S.5.N. | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. |
| irregular | A.IR.N, M.IR.N, S.IR.N | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | |||
| Custom | Alternate polish: | single side, double side optical, double side epi-ready, N-face epi-ready only | This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | ||
| Don’t see what you need? This e-mail address is being protected from spambots. You need JavaScript enabled to view it. | |||||
Specification Sheet Characterization Methods
Characterization of gallium nitride wafers as shown in our specification sheets is completed using the following methods:
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Wafer thickness, Bow and TTV are determined by a Sigmatech thickness mapper for round substrates. Square substrates are measured manually at predetermined points on the wafers.
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Wafer orientation is determined by x-ray diffraction
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Conductivity is determined by Lehighton (n-type, semi-insulating) and/or Corema measurements (semi-insulating) and/or Hall measurements for our boule recipes, but are not made on all wafers shipped.
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Dislocation density is determined via etch pit density measurements followed by AFM and/or micro-cathodoluminescence (Micro-CL), but are not made on all wafers shipped.
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Macro defects are on the surface of the wafer and are counted by visual inspection.
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Surface roughness information is determined by atomic force microscopy (AFM) for the front surface finish. The typical image size for the measurement is 20x20 microns.