In-situ Wafer Temperature Measurement

NTM W (Non-Contact Low Temperature Monitor)

 

The NTM-W is an infrared radiometer, optimized for temperature measurement of opaque targets starting from below room temperature.   

The high sensitivity and broad dynamic range allow very low temperatures to be accurately measured.   Application dependent algorithms allow for subtraction of interfering background radiation.

Flexible design for OEM applications, allows up to four probes to measure synchronically, providing a cost effective measurement of several targets, or the uniformity of a single target.

 

Features and Benefits

  • In situ, Real-time non-contact temperature monitoring.
  • On-the-fly Emissivity input for real time emissivity compensation
  • High sensitivity and wide dynamic range
  • Miniature probe head size (customized probe configurations)
  • Rapid update rate (up to 250Hz) for closed loop control.
  • Temperature readout via digital (RS232) or analog (4-20ma) outputs.
  • Proprietary algorithms for background compensation
  • Single-channel or multi-channel configuration
  • Synchronized operation - Up to 4 probes inherently synchronized
  • Flexible design for OEM use
  • Advanced, user friendly s/w for set-up, calibration and data-logging.

 

Typical Applications

Any opaque targets that require non contact monitoring such as: Glass substrates, Sapphire substrates,  Metals components, moving targets, Liquids etc.

  • Silicon
  • Glass
  • Metals
  • Liquids

 

Key Specifications

Temperature range

Standard model:  -40 to 800°C.

Accuracy

Greater of  1°C or 1% of °C reading

(Ambient 18-28*C, target emissivity 1, target temperature > 0°C)

NET

0.03°C + abs(T-50°C)/5000,   for target emissivity = 1

Response time (63%)

4 probe x 50Hz option: 140ms

1 probe x 250Hz option 10ms

Spot size

Hardware configurable (at factory) per application requirements:

Example: Fixed focus at  110mm

 

Measurement rate

250Hz for single probe +  controller

50Hz for 4 probes connected to one controller

Stray radiation compensation

Controller includes 4 K-type thermocouple inputs, which can optionally be used to measure the temperature of, and compensate for, stray radiation sources in the process chamber.  Appropriate for systems containing hot surfaces (example: a hot chuck) which are not directly viewed by the NTM-W probe, but that contribute radiation via reflection off the process wafer.

Measurement synchronization

All probes measure simultaneously when connected to the same controller.

Embedded PID option

Embedded PID control calculation in the NTM-W controller (one independent PID loop per each of the 4 temperature channels,)  allows output of PID control signal directly to each of the 4 NTM-W analog outputs (4-20mA).

Communication

4-20mA (4 per controller unit) , and RS232 or RS485

Dimensions

Probe: 30x20x71mm

Controller: 113x133x38mm