Furnaces for Contact Annealing

Jane is a chemical engineer working in a processing division of a large semiconductor fabrication facility. She is tasked to order new furnaces for annealing indium, zinc, and gold contacts. A different furnace is used for each metal. Furnaces vary in price and have different operation temperatures, as shown in the table below:

Furnace

Price

Operation Temperature (F)

MTX 120

$150

50 to 250

MTX 150

$180

100 to 400

MTX 250

$250

100 to 600

MTX 350

$350

200 to 800

MTX 500 HT

$600

250 to 1,300

Jane wants to order three MTX 120 furnaces first. Then, she remembers that operation temperature of furnaces should be at least 50 K (degrees Kelvin) above annealing temperature.

Annealing temperatures are provided in the table below:

Metal

Annealing Temperature (C)

Gold

600

Indium

90

Zinc

250

What furnaces should Jane select to save money for the company? How can she explain her decision in the report she will submit to her manager?