Precise measurements are required in the photolithography portion of processing wafers. During the numerous times when a given wafer is in a photolithography tool for subsequent layers of the circuit to be patterned, a change in temperature of more than +/- 1 degree will cause alignment defects that could significantly reduce the yield on the wafer.

The high-power lamp used in the photolithography process generates a lot of heat inside the tool.  This heat must be monitored and balanced with the right amount of cooling air to keep the tool interior and wafers at a constant temperature. The PDT-440 thermistor transmitter, or the PDT-444 high accuracy 4-wire transmitter can be used in conjunction with a high-stability, fast-response thermistor to monitor and control these air flows. With the PDT-444, control to +/- 0.01C is possible.

In processes such as the manufacture of flat panel glass for television or computer displays, precise temperature control is critical in the formation of flat, smooth, defect free glass. The glass must be cooled at controlled rates to guarantee the desirable mechanical properties of strength and rigidity. Ultra-fast response thermocouples are used to measure the surface temperature of the glass sheet as it cools to insure these properties will be achieved. The thermocouple measurement junction is .005” in diameter to assure the desired ultra-fast response.

These probes can be supplied in lengths up to 7 feet long and are specially designed to allow for high rates of thermal expansion without damaging the delicate measurement junction.

Ion Implantation is a critical step in the manufacture of semiconductors. High energy implantation can heat the wafer and cause problems that lead to yield reduction. Monitoring the temperature of wafers during implantation is required to determine the amount of wafer cooling that is required.

Small-diameter, fast-response, spring-loaded thermocouples such as those shown above are an economical and reliable way to monitor ion implantation tool temperature.

Conax offers a Single-Point calibration thermocouple designed for use on Applied Materials/Moore Technologies 76XX, 77XX and 78XX Series Epitaxial Barrel Reactors.

The Single-Point sensor allows for the calibration of the 3 infrared (IR) sensors used to monitor susceptor temperature during wafer processing. The Single-Point needs to be repositioned in the susceptor to check the calibration of each or the 3 IR sensors. The Single-Point sensors use K-Type thermocouple wire and a Haynes 214 sheath.

Conax offers a complete selection of both OEM Triple-point calibration thermocouples and special variations that have been customized based on individual fab needs. The Triple-point was designed for use on Applied Materials/Moore Technologies 76XX, 77XX and 78XX Series Epitaxial Barrel Reactors.

The Triple-point sensor allows for the calibration of the 3 infrared (IR) sensors used to monitor susceptor temperature during wafer processing. Because the sensor has 3 measurement junctions, all 3 IR sensors may be calibrated at one time. This saves time and increases repeatability over a single junction sensor because the Triple-point does not have to be re-positioned to calibrate each IR sensor.

The three junctions are precisely located. All units are shipped with a two-temperature calibration, typically at 1100C and 1200C or at customer requested temperatures. Triple-point sensors use C-Type thermocouple wire and Inconel sheath material unless designed otherwise by the customer.

Conax also offers an inspection and recalibration service recommended annually. The inspection includes an X-ray to determine the condition of the internals of the Triple-point sensor.