Specifying a Replacement IR Lamp for Semiconductor Equipment
A complete replacement-lamp request requires more than “same watts, same length.” It needs a controlled specification covering the lamp, electrical circuit, mounting arrangement and thermal process. Omit any one of these elements and the lamp may fit the drawing but fail in the machine—or operate normally while changing the wafer temperature profile.
Start with the original evidence
Collect the equipment manual, lamp label, OEM part number, electrical schematic and a dimensioned drawing. Photograph the lamp before removal, including both terminals, lead exits, reflector orientation and mounting clips. Record which lamp position it occupied; systems with multiple zones may use visually similar lamps with different ratings. If the old lamp is broken or unreadable, do not infer its rating from a neighboring lamp until the schematic confirms they are the same circuit.
Define the mechanical envelope
Specify at least:
- overall length and effective heated length;
- quartz-tube diameter and tube count;
- cold end and seal dimensions;
- base or terminal type, lead length and lead exit direction;
- reflector coverage and its angular orientation;
- mounting points, free-expansion direction and dimensional tolerances. “Length” is ambiguous. One supplier may quote tip-to-tip length while another uses heated length. Put both on a drawing and state the measurement reference points.
Match the electrical system
Record the rated voltage and power of each lamp, not just the complete bank. Also document the circuit grouping, controller type, switching method, protection and connector temperature rating. At rated steady state, the approximate current of a resistive lamp is P ÷ V, but this simple calculation does not establish that one lamp can replace another. Cold resistance, inrush behavior, controller limits and supply variation still matter.
A higher-power lamp can overload wiring, switches, solid-state controllers, sockets or cooling. A lower-power lamp may prevent the process from reaching its validated temperature ramp. Equal wattage at a different voltage is not an equivalent load.
Describe the optical configuration
State whether the original tube is clear, ruby, half-white, half-gold or fully reflector-coated. Include the direction in which the reflector faces. The coating changes the direction of the radiation, so it is part of the heating geometry rather than a cosmetic finish. Also state whether the process calls for short-, medium- or another wavelength range. The target film, wafer surface, quartz window and chamber surfaces do not absorb all wavelengths equally. NIST research on rapid-thermal-processing thermometry shows that wafer and chamber radiative properties and geometry affect the measurement model. That is why “more infrared” is not a complete thermal specification.
Define acceptance before ordering
Agree on documentation and tests:
- drawing approval and nameplate verification;
- visual inspection of quartz, seals, coating and terminals;
- cold-resistance comparison within the supplier’s stated tolerance;
- fit check without forcing the seals or leads;
- controlled low-risk energization under the equipment procedure;
- current and zone-response check;
- temperature mapping with non-product or engineering wafers;
- recipe and process-result comparison before production release. A lamp supplier can confirm the manufactured lamp. Only the equipment owner can validate the process result in the actual chamber.
Send the controlled specification
Goldisgood lists a custom high-power short-wave quartz IR lamp for semiconductor wafer heating. Its catalog records configurable voltage, power, length and reflector options. Treat those ranges as manufacturing options, not proof of drop-in compatibility; send the complete specification above for model confirmation.
Frequently asked questions
Is the OEM part number enough?
It is the best starting point, but the drawing and electrical specification should also be confirmed in case of undocumented revisions or mislabeled stock.
Can the old lamp be copied from a physical sample?
Dimensions and terminals can be measured, but voltage, power, optical output and process history may not be recoverable from the sample alone.
What is the final pass/fail criterion?
Mechanical fit and electrical operation are necessary. The final criterion is the validated wafer or package process result under the approved recipe. Continue with single- versus twin-tube selection and reflector-finish selection.
Sources
- NIST, Effects of Wafer Emissivity on Rapid Thermal Processing Temperature Measurement
- ORNL, Thin Film Deposition & Reactive Ion Etching facility
- Goldisgood product catalog, reviewed 2026-08-11