PRODUCT INFORMATION

characteristic

The head integrates the necessary functions for measuring film thickness
Measurement of high-precision absolute reflectance (multilayer film thickness, optical constants) using microspectroscopy
1:1 high-speed measurement
Optical system with a wide range under microscopic spectroscopy (ultraviolet to near-infrared)
Security mechanism of regional sensors
Easy to analyze guide, beginners can also perform optical constant analysis
Independent measuring heads correspond to various inline customization requirements
Support various customizations

Measurement items:
Absolute reflectance measurement
Analysis of multilayer films
Optical constant analysis (n: refractive index, k: extinction coefficient)

Measurement example:
Measurement of Film Thickness of SiO 2 SiN [FE-0002]

Semiconductor transistors send signals by controlling the conduction state of current, but in order to prevent current leakage and the flow of current from another transistor through any path, it is necessary to isolate the transistor and embed an insulating film. SiO2 (silicon dioxide) or SiN (silicon nitride) can be used for insulating films. SiO2 is used as an insulating film, while SiN is used as an insulating film with a higher dielectric constant than SiO2, or as an unnecessary barrier layer for removing SiO2 through CMP. Afterwards, SiN was also removed. It is necessary to measure the thickness of these films for the performance of insulation films and precise process control.

Measurement of Film Thickness of Color Resist (RGB) [FE-0003]

The structure of a liquid crystal display is usually shown in the figure on the right. CF has RGB in one pixel and it is a very fine micro pattern. In the CF film formation method, the mainstream approach is to apply pigment based color resist on the entire surface of glass, expose and develop it through photolithography, and leave only patterned portions at each RGB point. In this case, if the thickness of the color resist is not constant, it will cause pattern deformation and color changes as a color filter, so it is important to manage the film thickness value.

Measurement of Hard Coating Film Thickness [FE-0004]

In recent years, products using high-performance films with various functions have been widely used, and depending on the application, it is also necessary to provide protective films with properties such as frictional resistance, impact resistance, heat resistance, and chemical resistance of the film surface. Usually, the protective film layer is formed using a hard coating (HC) film, but depending on the thickness of the HC film, it may not function as a protective film, causing warping, uneven appearance, and deformation in the film. Therefore, it is necessary to manage the film thickness value of the HC layer.

Considering the film thickness value measured for surface roughness [FE-0007]

When there is roughness on the surface of the sample, mixing the surface roughness with air and film thickness material in a 1:1 ratio to simulate a "roughness layer" can be used to analyze the roughness and film thickness. Here is an example of measuring the surface roughness of SiN (silicon nitride) with a few nm.

Measurement of interference filter using superlattice model [FE-0009]

When there is roughness on the surface of the sample, mixing the surface roughness with air and film thickness material in a 1:1 ratio to simulate a "roughness layer" can be used to analyze the roughness and film thickness. Here is an example of measuring the surface roughness of SiN (silicon nitride) with a few nm.

Measurement of encapsulated organic EL materials using a non-interference layer model [FE-0010]

Organic EL materials are susceptible to the effects of oxygen and moisture, and they may deteriorate and be damaged under normal atmospheric conditions. Therefore, glass sealing is required immediately after film formation. This shows the measurement of film thickness through glass in a sealed state. The glass and intermediate air layer use a non-interference layer model.

Using multi-point similarity analysis to measure unknown ultra-thin nk [FE-0013]

In order to analyze the film thickness value (d) by fitting the least squares method, material nk is required. If nk is unknown, both d and nk are analyzed as variable parameters. However, in the case of ultra-thin films with d of 100nm or less, d and nk cannot be separated, resulting in reduced accuracy and the inability to accurately determine d. In this case, measuring multiple samples with different d, assuming nk is the same, and conducting simultaneous analysis (multi-point identical analysis), can accurately and precisely determine nk and d.

Measure the film thickness of the substrate using interface coefficient [FE-0015]

If the substrate surface is non mirror and has a high roughness, the measured light will decrease due to scattering, and the measured reflectivity will be lower than the actual value. By using interface coefficients, the thickness of the thin film on the substrate can be measured, taking into account the decrease in reflectivity on the substrate surface. As an example, demonstrate the measurement of the film thickness of resin film on a finished aluminum substrate with hair strands.

Measurement of DLC coating thickness for various purposes

DLC (diamond-like carbon) is an amorphous carbon based material. Due to its high hardness, low friction coefficient, wear resistance, electrical insulation, high barrier properties, surface modification, and affinity with other materials, it is widely used for various purposes. In recent years, the demand for membrane thickness measurement has also increased according to various applications.

The general approach is to perform destructive DLC thickness measurements by observing the cross-section of the prepared monitoring sample using an electron microscope. The optical interference type film thickness gauge used by Otsuka Electronics can perform non-destructive and high-speed measurements. By changing the measurement wavelength range, it is also possible to measure a wide range of film thicknesses from ultra-thin films to ultra thick films.

By using our own microscope optical system, not only can we measure and monitor samples, but we can also measure shaped samples. In addition, the monitor can also be used to analyze the cause of abnormalities by confirming the measurement position while conducting measurements.

Support customized tilt/rotation platforms that can correspond to various shapes. It can measure any number of positions on the actual sample.

The weak point of the optical interference film thickness system is that it cannot accurately measure the film thickness without knowing the optical constant (nk) of the material. Otsuka Electronics confirmed this by using a unique analysis method: multi-point analysis. Measurement can be carried out by simultaneously analyzing samples with different thicknesses prepared in advance. Compared with traditional measurement methods, it can achieve extremely high accuracy in NK.
Calibration is carried out using standard samples certified by NIST (National Institute of Standards and Technology) to ensure traceability.