_FR-Liquid |
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Description
FR-Liquid is a table-top optical instrument for the real time monitoring of changes in thickness and optical constants of thin/thick (n & k) films during processing in liquids (Fig.1). FR-Liquid’s principle of operation is based on the White Light Reflectance Spectroscopy (WLRS) and exploits the FR-Basic platform with the addition of a Teflon cell for hosting the sample under investigation (Fig. 2a, 2b). In this tool thereflection probe is mounted horizontally outside the Teflon cell at a very short distance from the glass window. A stirrer located below the cell provides for mechanical agitation of the solution during the process if necessary. The vertical sample holder is designed to accommodate small silicon samples of arbitrary shape as well as whole Si wafers (3”, 4” diameter).
The tool is controlled by the FR-Monitor software, performing the data acquisition and film thickness and optical constants calculations. A material database is included and can be easily expanded by the user. The entire system (hardware – software) is shipped ready for measurements: light source, spectrometer, bifurcated optical fiber, stirrer, vessel, sample stage, Windows™ software and can be easily used by anyone with basic computer skills without any deep knowledge of optics. The only additional part needed is a computer with a free USB port running Windows XP/Vista/7 Operating system |
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Fig.2 The Sample just before enter in to Teflon cell (a), and during the dissolution measurement (b). Behind the Teflon cell are distinguished the pipes for the cooling of the liquid under the room temperature. |
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Depending on the characteristics of the dissolution process, e.g. the dissolution speed, the monitoring is performed either off-line or in real time. In all cases the reflectance data are stored for subsequent processing. By using a particular film stack the monitoring of the dissolution process is possible even for polymeric (photoresist) films with thickness of few tens of nm. In FR-Liquid, critical phenomena such as swelling are also monitored. For thickness measurements, all that is required in most cases is a smooth, reflective substrate. For optical constant measurements, a flat reflecting substrate is required. If the substrate is transparent, then its backside should be non reflective. The FR-Liquid software can handle layer stacks consisted of numerous layers and two quantities can be calculated simultaneously e.g. the thicknesses of two films or the thickness and n & k of one film etc |
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| Fig.3 Dissolution measurement of various thickness PMMA films |
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The FR-Liquid tool has been successfully applied for the evaluation of the dissolution process of various smooth, transparent or lightly absorbing films over reflecting substrates (Si wafer). Films studied include: SiO2, SiNX, Photoresist, Polymer layers. |
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Specifications*** |
Applications |
| Thickness |
5nm – 150μm* |
Polymer Characterization |
| Wavelength range |
200-1100nm* |
Photopolymer Characterization |
| Accuracy |
0.5 % |
Biomedical |
| Precision |
0.02nm |
Semiconductor |
| Spot size |
0.5mm |
non Metal Films |
| Sample size |
10 - 150mm, iregular shape |
Optical Coating |
| Computer requirements |
PC with Windows XP/Vista and a USB port available |
Hardcoats |
| Power requirements |
110V/230V AC |
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| Dimensions (WxLxH) |
360mm x 400mm x 180mm** |
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| Weight |
15Kgr* |
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* Depends on the specification, please refer to FR-Basic page. |
** In the height measurement the cover top is not included |
*** Specifications are subject to change without any notice. |
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