To measure various properties of optical thin film, researchers are required to indirectly measure the optical response which is directly attributed to various factors such as the reflectivity of the film, transmittance or ellipsometry parameters, rather than the properties associated with the filmstack.
Furthermore, once the optical response measurements are acquired, it is imperative for the user to create an optical model of the filmstack structure. From this structure, the user can determine the “inverse” problem to ultimately establish what the actual physical properties of the film are, such as the thicknesses of the layers and optical constants of the layer’ materials.
By floating selected filmstack parameters, users can generate a best fit that infers the “measured” parameters. In order to ensure that the most reliable results are being acquired, it is highly recommended for users to confirm the validity of their selected optical model, as well as the parameters’ correlation and sensitivity within the measured data of parameters of interest in the context of the specific instrument and measurement recipe.
In this regard, the TFCompanion software is used to simplify each of these tasks by increasing their transparency through a combined series of analytical tools that are used to interpret any measured data. For example, simulation and sensitivity analysis allows the user to test and optimize the measurement strategy which can consist of selecting the spectral range, resolution, angle and/or measurement method.
The software’s ‘Error Estimator’ also provides users with an estimation of the measurement precision that, while repeatable in the short term, is based on the specific recipe measurement and sample. Through the use of these tools, users can both develop a reliable and comprehensive measurement strategy while also mitigating any potential trade-offs that may exist between the accuracy of the acquired measurements and time/throughput.
TFCompanion also provides users with various different features that have been shown to dramatically increase the productivity and ease of use of probes associated with this software. For example, Global Search algorithm has evaluated the use of a single filmstack model for the full range of film thickness, which was originally based on PSD/FFT analysis and the thickness order search.
On the other hand, the ‘multiple filmstacks’ algorithm instead adds several filmstacks to calculation recipe that allows a single model/recipe to be applied for a range of sample types. Batch processing allows for a large number of measurements to be processed unattended, thereby allowing the user to perform other important tasks during this procedure.
TFCompanion provides a flexible configuration of features, capabilities and access levels, all the while supporting both standalone and connected modes. When in the standalone mode, all measured data can be easily imported and analyzed off-line. Whereas the connected mode allows for data to be easily and directly acquired from the spectrometer.
Additionally, users can also send data through the TCP/IP (socket) interface, as well as a number of other available integration modes, when in the connected mode. Note that different modes, such as the Administrator, Engineer and Operator User levels, provide different access privileges and features, depending upon the user level.
Three Main Functions
- Calculate: Determine filmstack parameters based on measured data
- Simulate: Measurement sensitivity to and optical response from filmstack
- Estimate: Measurement precision/ repeatability and optimize measurement recipe
- Flexible system
- Easily import data from files that have been previously transferred over TCP/IP or directly taken from the spectrometer
- Supports Windows, Linux and Mac OS Desktop or server mode
- 500+ Materials Library
- User can easily add new materials
- Supports parameterized materials:
Advanced features that include Calculation Strategy, Global Search and Thick Film Algorithm enable the use of one recipe for a wide range of filmstacks.
“Preflight” Error Estimate check allows optimization of the measurement strategy. Parameters Correlation and Confidence Intervals information guides the data analysis optimization.
Software for Thin Film Analysis - TFCompanion
Thickness mappings results (200pts)
Mapping setup and analysis
10 x 10 um etched pattern in SiO2 (Imaging Ellipsometry)