=== Etch Rate Uniformity Analyzer ===
Version: v1.0
Platform: Windows, Python 3.8+

[Function]
Built-in 9-point wafer thickness (before/after etch) data, calculates:
  - Etch rate per point (nm/s)
  - Mean etch rate
  - 1-Sigma uniformity
  - Range (%) non-uniformity
Plots: 9-point bar chart, wafer contour map, uniformity metrics.

[Usage]
1. Run: python 刻蚀速率均匀性分析器.py
2. Adjust etch time and click "Calculate"
3. Or click "Example Data"

[Built-in Data]
Before thickness: [520,510,505,515,500,510,518,512,508] nm
After thickness:  [120,115,110,118,108,115,122,116,112] nm
Etch time: 120 s

[Dependencies]
Python 3.8+, numpy, matplotlib
