Dynamics and control of the Czochralski process IV. Control structure design for interface shape control and performance evaluation
Abstract
Analysis of a low order model of the Czochralski process reveals the performance limitations in controlling both the crystal diameter and interface shape for both feedforward and feedback structures. A new control structure is proposed that maintains crystal diameter, interface shape, and thermal gradients throughout the batch growth cycle. Performance of alternative control structures are evaluated.
- Publication:
-
Journal of Crystal Growth
- Pub Date:
- May 1994
- DOI:
- 10.1016/0022-0248(94)90178-3
- Bibcode:
- 1994JCrGr.139..286G
- Keywords:
-
- Control Systems Design;
- Czochralski Method;
- Dynamic Control;
- Feedback Control;
- Feedforward Control;
- Performance Tests;
- Shape Control;
- Temperature Gradients;
- Controllers;
- Crystals;
- Solid-State Physics