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

TaC-Coating-with-High-Crystallinity-and-Uniformity-40
40µm
TaC-Coating-with-High-Crystallinity-and-Uniformity-02
40µm

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
1x10-5
>2200 °C
0.2
0.1
~5%
SiC
3.2
0.8
4.5
2800
2x10-3
<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

TaC Coated Graphite Furnace Components

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