Lam® 4520Xle

Lam® 4520Xle

Lam® 4520Xle Temperature Profiles using LAUDA-Noah DAQ

Process: Oxide Etch - 200mm
RF Power: Varies
T Set-point: 40 °C upper electrode
T Set-point: 10 °C lower electrode
(*) Chiller: compressor-based chiller vs. LAUDA-Noah POU system

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

Conventional, compressor-based chiller profiles

The fluid temperature profiles below were captured during a production run. This revealing data shows fairly significant fluid temperature variances and fluctuations of the upper and lower loop, per wafer and through-the-lot. This data is very typical of any compressor-based chiller that utilizes a large fluid reservoir and located in the sub-fab:

LAUDA-Noah POU chiller system profiles

The fluid temperature profiles below were also captured during a production run under "identical conditions" as the previous data-set. This comparative data clearly shows an improvement in fluid temperature stability and uniformity, per wafer and through-the-lot. The data below is a compelling illustration of Dynamic Temperature Control and demonstrates the POU systems ability to "synchronize with the process"...

Upper Electrode Results

Compressor-based chiller

  • non-repeatable temperature profile from the TCU, with drastic temperature fluctuations towards the end of the recipe
  • 5.2 °C drift per wafer (38.4 °C vs. 43.6 °C)
Lam upper compressor

Point-of-use Chiller

  • minimal fluctuations during wafer processing
  • improvement ~60% (2.1 °C vs. 5.2 °C)
  • dynamic temperature control
Lam upper pou
Lower electrode results

Compressor-based chiller

  • large fluctuations of the fluid temperature are observed during the recipe, with lower electrode temperatures reaching <14 °C
  • 6.3 °C drift per wafer @ 7.8 ~ 14.1 °C
Lam lower compressor

Point-of-use Chiller

  • no major temperature fluctuations
  • improvement ~46% (3.4 °C vs. 6.3 °C)
  • dynamic temperature control
Lam lower pou