Aluminum Oxide (Al2O3) Pieces Overview
We sell these pellets and pieces by unit weight for evaporation use in deposition processes. These approximate materials prices are published to provide budgetary guidelines. Actual prices can vary and may be higher or lower, as determined by availability and market fluctuations. To speak to someone directly about current pricing, please click here .
Aluminum Oxide (Al2O3) General Information
Aluminum oxide, or more commonly called alumina, is a chemical compound with a chemical formula of Al2O3. It is generally white or clear in appearance with a melting point of 2,072°C, a vapor pressure of 10-4 Torr at 1,550°C, and a density of 3.97 g/cc. It is most commonly found in nature as the mineral corundum, from which ruby and sapphire are derived. Aluminum oxide is used extensively as an abrasive and is utilized in various industrial applications. It can also be found in paint, cosmetics, and surgical implants. It is evaporated under vacuum to form dielectric films for the semiconductor industry and as a mirror-like protective layer for optical coatings.
Aluminum Oxide (Al2O3) Specifications
Material Type | Aluminum Oxide |
Symbol | Al2O3 |
Color/Appearance | White, Crystalline Solid |
Melting Point (°C) | 2,072 |
Theoretical Density (g/cc) | 3.97 |
Z Ratio | 0.336 |
E-Beam | Excellent |
Thermal Evaporation Techniques |
Boat: W Basket: W |
E-Beam Crucible Liner Material | FABMATE®, Tungsten |
Temp. (°C) for Given Vap. Press. (Torr) | 10-4: 1,550 |
Comments | Sapphire excellent in E-beam; forms smooth, hard films. |
Suggested QCM Crystal | Alloy Crystal: 750-1002-G10**** |
**** Suggestion based on previous experience but could vary by process. Contact local KJLC Sales Manager for further information
Empirical Determination of Z-Factor
Unfortunately, Z Factor and Shear Modulus are not readily available for many materials. In this case, the Z-Factor can also be determined empirically using the following method:
- Deposit material until Crystal Life is near 50%, or near the end of life, whichever is sooner.
- Place a new substrate adjacent to the used quartz sensor.
- Set QCM Density to the calibrated value; Tooling to 100%
- Zero thickness
- Deposit approximately 1000 to 5000 A of material on the substrate.
- Use a profilometer or interferometer to measure the actual substrate film thickness.
- Adjust the Z Factor of the instrument until the correct thickness reading is shown.
Another alternative is to change crystals frequently and ignore the error. The graph below shows the % Error in Rate/Thickness from using the wrong Z Factor. For a crystal with 90% life, the error is negligible for even large errors in the programmed versus actual Z Factor.
Thermal Evaporation of Aluminum Oxide (Al2O3)
Thermally evaporating aluminum oxide is very difficult due to the high temperature required to heat the material to temperatures hot enough to allow for reasonable deposition rates. The temperature limitations on the evaporation sources currently available also make thermal evaporation challenging. E-beam evaporation or sputtering are the preferred methods for depositing aluminum oxide films.
If thermal evaporation is the only option, we would recommend a tungsten dimple boat such as our EVS8B005W. The lifetime of the boat will be limited, as the aluminum oxide will eventually start to react with the boat during the evaporation process. Achieving high enough temperatures to evaporate from a crucible or alumina-coated source are likely in excess of those temperatures deemed reasonable in a vacuum chamber or limited by the power supply.
We estimate a deposition rate of 2-5 angstroms per second when the evaporation temperature is at ~2,100°C. A partial pressure of O2 at 1 X 10-5 Torr is recommended. It is important to note that evaporation temperatures likely exceed the temperatures reasonable to evaporate via resistive heating.
E-beam Evaporation of Aluminum Oxide (Al2O3)
E-beam evaporation is preferred for depositing aluminum oxide films as the material is rated excellent for this method. We recommend evaporating from a FABMATE® or tungsten crucible liner or directly from the copper hearth.
Sweep the e-beam at low power to fully melt the material and avoid hole drilling. We estimate a deposition rate of 2-5 angstroms per second when the evaporation temperature is at ~2,100°C. A partial pressure of O2 at 1 X 10-5 Torr is recommended. The material should be replaced when it becomes dark or black.
Another process note is to consider the fill volume in the e-beam application because we find that the melt level of a material in a crucible directly affects the success of the crucible liner. Overfilling the crucible will cause the material to spill over and create an electrical short between the liner and the hearth. The outcome is cracking in the crucible. This is the most common cause of crucible liner failure. Placing too little material in the crucible or allowing the melt level to get too low can be detrimental to the process as well. When the melt level is below 30%, the e-beam is likely to strike the bottom or walls of the crucible which immediately results in breakage. Our recommendation is to fill the crucible between 2/3 and 3/4 full to prevent these difficulties.
Because not using a crucible liner is not always an option (especially in shared systems), some customers will use a copper crucible liner and place the material in the copper crucible liner as opposed to placing directly in the hearth. Crucible liners should be stored in a cool, dry place and always handled with gloves or forceps.
See highlighted results that match your result in the table below.
Ordering Table
Material | Description | Size | Quantity | Purity | Part Number | Price | In Stock | Add To Cart | |
---|---|---|---|---|---|---|---|---|---|
Material | Description | Size | Quantity | Purity | Part Number | Price | In Stock | Add To Cart | |
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 2.5mm Pieces | 1 kg | 99.99% | EVMALO-1-2.5 | $305.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 2.5mm Pieces | 100 g | 99.99% | EVMALO-1-2.5D | P.O.R. | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 3mm Pieces | 25 g | 99.99% | EVMALO1-3MMA | $46.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 3mm Pieces | 50 g | 99.99% | EVMALO1-3MMB | $60.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 3mm Pieces | 100 g | 99.99% | EVMALO1-3MMD | $108.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 3mm Pieces | 1 kg | 99.99% | EVMALO1-3MMKG | P.O.R. | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 3mm Pieces | 500 g | 99.99% | EVMALO1-3MMT | P.O.R. | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 5mm Pieces | 1 lb | 99.99% | EVMALO-1220 | P.O.R. | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 5mm Pieces | 25 g | 99.99% | EVMALO-1220A | $71.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 5mm Pieces | 50 g | 99.99% | EVMALO-1220B | $100.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 5mm Pieces | 100 g | 99.99% | EVMALO-1220D | $185.00 | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 5mm Pieces | 1 kg | 99.99% | EVMALO-1220KG | P.O.R. | |||
Aluminum Oxide |
ALUMINUM OXIDE PIECES, |
1mm - 5mm Pieces | 500 g | 99.99% | EVMALO-1220T | P.O.R. |