Ceramics Products
TaC Coated Graphite Furnace Components
For SiC and AIN Crystal Growth
Momentive Performance Materials Inc. offers a proprietary coating technology known as Tantalum Carbide (TaC) coating. With its high temperature stability, high purity and high chemical resistance, TaC suppresses contamination in contact with graphite, extends graphite component life, and
maintains sublimation stoichiometry.
Ultimately, TaC coated graphite components improve process yield and crystal quality in the SiC and AlN crystal growth, via physical vapor transport (PVT) and high-temperature chemical vapor deposition (HT-CVD).
Key Features
- Temperature stability > 2200 °C
- Ultra high purity
- Resistance to Si and H
- Resistance to thermal stock
- Strong adhesion to graphite
- Conformal coating coverage
- Size up to 750 mm diameter
Potential Applications
- Crucible
- Lid
- Seed holder
- Ring
- Injector
- Susceptor
TaC Coating with High Crystallinity and Uniformity
Comparison of TaC Coating and Purified Research Grade Graphite
| Unit (ppm. wt.) | B | N | O | Si | S | Cl | Nb |
|---|---|---|---|---|---|---|---|
|
TaC |
<0.01 |
15 |
40 |
<0.01 |
<0.01 |
14 |
14 |
|
Graphite |
1 |
480 |
260 |
2 |
5 |
2 |
<0.01 |
Comparison of Typical Defects in SiC Wafers Grown with TaC Coated Graphite Crucible and Conventional Graphite Crucible
Comparison of Electrical Properties of SiC Wafers Grown with TaC Coated Graphite Crucible and Conventional Graphite Crucible
| Bulk Concentration | Bulk Resistivity | Mobility | |
|---|---|---|---|
|
TaC |
8 x 1015/cm |
4.5 ohm-cm |
237 cm2/Vs |
|
Graphite |
5 x 1017/cm |
0.1 ohm-cm |
151 cm2/Vs |
Typical Property Comparison of TaC and SiC Coatings
| Density (gm/cm3) | Emissivity(1) | CTE (x10-6/K) | Hardness (HK) | Resistance (Ohm-cm) | Thermal Stability | Etch Rate(2) in NH3 (μm/hr) | Etch Rate(3) in H2 (μm/hr) | Thickness Variation | |
|---|---|---|---|---|---|---|---|---|---|
|
TaC |
14.3 |
0.3 |
6.3 |
2000 |
1×10-5 |
>2200 °C |
0.2 |
0.1 |
~5% |
|
SiC |
3.2 |
0.8 |
4.5 |
2800 |
2×10-3 |
<1600 °C |
1.5 |
1.7 |
~10% |
Note: Test data. Actual results may vary.
Typical properties are average data and are not to be used as or to develop specifications.
(1) Emissivity is measured at 950nm and 1000 °C.
(2) Etch rate in NH3 is measured at 1400 °C and 500 Torr.
(3) Etch rate in H2 is measured at 1400 °C and 760 Torr.
Download the product datasheet
