Applied Materials® High Aspect Ratio Trench Etch (HART) 300mm Temperature Profiles using LAUDA-Noah DAQ

Process: Silicon Etch
RF Power: 3.3kW (avg.)
T Set-point: 50 °C at Cathode
(*) Chiller: OEM qualified heat exchanger vs. LAUDA-Noah POU system

The data acquisition equipment set-up is typical. We have documented the cathode cooling loop supply and return fluid temperatures at the request of the customer.

Conventional heat exchanger (HX) profiles

AMAT HART 300mm Static

The fluid temperature profiles below were captured during a production run. This data "snapshot" shows a very significant fluid temperature rise per wafer and includes a baseline temperature rise through-the-lot. The customer was very surprised to see these temperature excursions, considering the OEM qualified chiller was reporting a ~1 °C temperature variance through the entire process!! (shown as fluid supply temperature)

  • 2 season wafers due to 1st wafer effect
  • cathode temperature varies ~5 °C, per wafer
  • baseline temperature time rise through the lot
  • only HX reservoir temperature is maintained
  • HX does not respond to temperature changes in chamber

LAUDA-Noah POU chiller system profiles

AMAT HART 300mm Dynamic

The fluid temperature profiles below were captured during a production run under "identical conditions" as the previous data-set. The most compelling aspects of this comparative data-set are the temperature uniformity and rapid response (time) accomplished under extremely high RF power conditions. This data clearly demonstrates Dynamic Temperature Control. Note how the fluid supply temperature is changed to compensate for the changing process conditions, in real-time...

  • uniform temperature control, wafer-to-wafer
  • Cathode temperature varies ~1 °C
  • no season wafers needed - minimized 1st wafer effect
  • no change in baseline temperature
  • POU system is synchronized with the process

Results

  • eliminated season wafers and increased chamber throughput
  • vastly improved temperature uniformity, per wafer
  • reduced chiller Cost-of-Ownership by installing LAUDA-Noah POU system
  • customer replaced all OEM qualified heat exchangers with LAUDA-Noah POU systems for this critical process