The Nanometrics Nanospec AFT 4150 is an automated film thickness measurement system for semiconductor and materials science metrology. It employs visible-light reflectometry to measure film thickness and refractive index non-destructively by analyzing interference effects against a bare silicon reference. The instrument accommodates 3-inch to 6-inch diameter wafers and measures films from 100 Å to 50 µm in a single pass.
Technical Specifications
Measurement Principle: Reflectometry using visible light and optical interference.
Film Thickness Range: 100 Å to 50 µm.
Wafer Compatibility: 3-inch to 6-inch diameter wafers.
Refractive Index Measurement: Manual or automatic determination supported.
Multi-layer Capability: Simultaneous measurement of underlayer and outer film thickness via dedicated programs (4, 5, 6, 11, 253).
Wavelengths: Visible spectrum operation with selectable/adjustable wavelengths. Filters available for wavelengths below 460 nm.
Objective Lenses: Multiple lens options; critical focus procedures for films below 200 Å may require higher magnification objectives.
Gain Control: Adjustable photo intensity meter gain optimization.
Light Source: Halogen lamp with documented replacement procedures.
– Key Features
• Measures oxide on silicon, nitride on silicon, polysilicon on oxide, resist layers, and multi-layer stacks
• Precise focusing capability for ultra-thin films
• Adjustable optical gain for signal optimization
• Printer output support for results documentation
• Menu-driven character-based interface via integrated computer system
• Modular optical head design (7200-18 visible film thickness head)
– Typical Applications
Semiconductor process control, oxide/nitride layer characterization, resist metrology, and polysilicon film analysis across wafer fab and materials research environments.
– Compatibility & Integration
Standard AC power operation. Keyboard-driven control with printer output capability. Proprietary firmware supports measurement of stacked dielectric and conductive films on various substrates.
