As the semiconductor industry continues to fulfill Moore’s law, thin film thickness is one of the most rapidly scaled dimensions. Consequently, chip manufacturers must implement metrology systems that will be effective for statistical process control of ultra-thin dielectrics.
Ellipsometry is a non-destructive technique, capable of being used for any transparent and semitransparent medium. It can measure a wide range of layer thickness from a fraction of mono-atomic layer to several micrometers.
Ellipsometry allows the determination of the thickness of single layers and multi-layer stacks. In addition, it allows the absolute characterisation of optical properties of materials by extraction of the N and K data.
Using Spectroscopic Ellipsometry, up to 7 layers can be analysed simultaneously in one measurement in order to extract the thickness of every individual layer. Material optical properties also, can be obtained over a wide spectral range, from Deep UV to near InfraRed.
Unlike other optical techniques, this method requires neither reference sample nor reference beam like reflectometry. Moreover, ellipsometry has the advantage of high sensitivity due to the additional measurement of the phase of light at different wavelengths. As a consequence, it allows analysis of complex structures like multi-layers with rough interfaces and unknown material composition.
In the semiconductor industry, there is continuous demand for higher performance and denser integrated circuits. These requirements push the advancement of technology which requires solving of manufacturing challenges. A key to success is to understand the chemical, mechanical and physical properties of wide range of materials used in a typical integrated circuit.
The µSE tool is designed to measure thin film thickness and optical properties inside a <50µm test pad on semiconductor product wafers. The applied measurement technique for obtaining these parameters in a high accuracy and repeatable way is spectroscopic ellipsometry. The μSE tool uses optimized spectroscopic ellipsometer (SE) arms and optics for the measurement inside small boxes of patterned Si wafers.
Ellipsometry measures the phase of the reflected light from the sample, therefore it is relatively insensitive for intensity fluctuations. The raw measurement data represent the complex information from the layer stack which then need to be modeled optically. The measurement results are obtained through numerical regression process of the model data to the raw measurement spectrum.
Refractive optical design in compact realization: short optical path inside the measurement arms (reduced alignment artifact errors). Active temperature control: stabilized environment for system reli-ability enhancement. Uniqe patented high brightness light source for outstanding SNR. CCD detector array (spectrum is taken simultaneously at different wavelengths).
The Ideal thin Film characterization Tool for development & Pilot Line
The SE-3000 spectoscopic ellipsometer has been designed to fit the need of development and pilot line either for microelectronic, flat panels displays and coating industries. The SE-3000 is based on a GES5E; it can be mounted with two FOUP loadports, high speed stage, handling robot and a fast pre-alignment station for wafer to achieve equivalent throughput than production tools. The SE-3000 has the same characteristics than the GES5E in term of spectral range, Performances and spot size.
A top frame with Hepa Filter and a production type software can be added to the SE-3000.Request Info
Microspot spectroscopic ellipsometer for patterned wafer applications.
Features and System specifications: