Download PDF of this product from our 8th Ed. Catalog
Substrate Quartz Lamp Heaters
 |
Our quartz lamps are used as both sample/substrate heaters and internal bakeout heaters. The lamp is mounted in a catenary-shaped electropolished bright stainless steel reflector assembly nomimally 4" long. Power feedthroughs are ordered separately but the internal leads, insulated with a high-temperature, woven mineral fiber covering, are supplied.
The 500W quartz lamp's 'color temperature' is 3000K, indicating its maximum energy emission is at a wavelength of ~900nm*. Assuming it is a black body source, the fraction of total energy emitted in the IR range (700nm - 10,000nm) is ~91% while the fraction emitted in the UV range (100nm - 400nm) is ~0.2%**. The high IR component indicates these lamps are effective heaters but the minuscule UV component means these lamps are not effective at exciting electronic transitions in chemical bonds.
In sample/substrate heater applications, the major advantages of lamps over alternatives (exposed wire heaters or resistive graphite elements) are their tolerance for low partial pressures of O2—particularly important in oxide reactive deposition processes—and their easy replacement. In the typical installations, either a single lamp or an array is mounted in the vacuum chamber close to the substrate's back surface and radiation heat transfer raises the substrate's temperature. Regrettably, the most important question—what is the substrate's maximum temperature—is unanswerable since it depends on many factors including:
- The substrate's ability to absorb the thermal radiation
- The 'shape factor' between substrate and heater
- The substrate's re-radiation and conduction to its surroundings
- The substrate's specific heat
A more complete explanation of vacuum heating go to http://www.lesker.com/leskertech/subscribe.cfm, sign up, and download Volume 2 Issue 4 "Hot, Hot, Hot" of Lesker Tech. For tips on estimating and possibly raising substrate temperatures in specific installations write to techinfo@lesker.com.
When used for internal bakeout heater applications in place of external blanket heaters or panel ovens, the major advantage is: the lamps directly radiate the surfaces that need to be heated to outgas. In addition, the full 500W from the lamp must be absorbed by the chamber walls before it can be dissipated into the room. This is not the case for 500W external heaters.
The average lamp life is 2000 hours. We strongly urge users to only select replacement lamps that do not have easily evaporable metals (Cd, Zn, etc) in the braze or sealing materials which will quickly contaminate the chamber. Arrays of multiple lamps are available in triangular and other configurations.
* Calculated using: Planck's law of black body radiation
** Calculated using: Blackbody Radiation Applet
Ordering Table
| Description | Total Power (Watts) |
Number of Lamps |
PartNo | Price (USA) |
Add To Cart |
|---|---|---|---|---|---|
Questions? Email us: [USA] | [Canada] | [Europe] | [China] | [Rest of World]
Accessories Table
| Description | PartNo | Price (USA) |
Add To Cart |
|---|---|---|---|
Questions? Email us: [USA] | [Canada] | [Europe] | [China] | [Rest of World]