Thin film thickness and optical properties (such as ITO, OLED, LTPS, IGZO, SiNx, SiOx, photoresist, etc.) are vital parameters for process control. Utilizing Semilab's Spectroscopic Ellipsometer, fast and precise measurements can be conducted on panels of any size, comparable in speed to reflectometers.
With our advanced analysis software, various parameters can be determined including optical band gap energy, transmission, roughness, and crystallinity-related factors (in the case of LTPS).
The SiOx/Glass structure can be challenging to measure using conventional optical methods, but due to the ellipsometer principle employed in FPT, even such low-contrast structures can be accurately assessed.

To maintain the stability of thin film solar cell production, precise control over layer deposition and treatment processes is essential. Semilab offers various metrology solutions for characterizing the electrical and optical properties of these thin layers.
Utilizing Semilab's "Spectroscopic Ellipsometry" and "Spectroscopic Haze and Reflectance" techniques, complete characterization of layer thickness and other optical parameters can be achieved, even for multilayer structures.

Fourier Transform Infrared (FTIR) based on Michelson interferometry is a non-contact and non-destructive method used for monitoring semiconductor properties:

Interferogram Measurement: It rapidly and accurately measures the thickness of silicon epitaxy (EPI) using the sideburst position.
Reflectance Measurement: It determines the thickness of the transition region in silicon EPI samples, along with information about layer composition and dopant concentration, using optical modeling. BPSG Concentration Measurement: Semilab's SAM software analyzes the concentration of complex materials like BPSG in real-time using PLS calibration.
Transmission Measurement: It evaluates layer thickness and dopant concentration by analyzing absorption peaks. Additionally, it can analyze the hydrogen concentration in SiN layers and the lattice-bound oxygen concentration in high and low-resistance silicon.

Model-Based Infrared Reflectometry (MBIR) is a thin film metrology inspection system designed for process wafers. It offers fast, repeatable, and non-destructive measurements.
The IR series products use MBIR technology to provide high throughput and cost-effective measurements of dimensions, composition, and uniformity of etched structures and films used in integrated circuit manufacturing. This technology simplifies system calibration and eliminates substrate variations' impact on key layer measurements.
MBIR technology includes unique optics that suppress backside reflection and filter out extraneous data, improving analysis capabilities and measurement accuracy. There are two MBIR optics options with different spot size configurations: large spot optics for films and device area measurements on patterned wafers, and small spot optics for scribe line test structures on patterned wafers.

The maximum magnification achievable with a conventional optical microscope is limited to about 800-1000× due to the properties of light. For higher magnification, Scanning Electron Microscopes (SEMs) are typically used, with Transmission Electron Microscopes (TEMs) providing the highest magnification, even down to single atoms.
However, the Scanning Probe Microscope (SPM) serves a unique purpose for several reasons:
1.Preservation of Samples: TEMs require thin slicing of samples, often damaging them in the process. SPM, on the other hand, images surface structures at the atomic level without harming the sample.
2.Three-Dimensional Imaging: SPM microscopes provide three-dimensional imaging, even when evaluating two-dimensional information. In contrast, electron microscopes struggle to investigate a sample's surface structure effectively.
3.Non-Vacuum Operation: SPM operates in ambient conditions, unlike electron and optical microscopes that require a vacuum environment.
4.Measurement of Physical Properties: SPM can measure various physical properties, including electrical properties (e.g., Kelvin probe force microscopy, KPM/KPFM) and magnetic properties (Magnetic force microscopy, MFM). This versatility sets it apart from other microscopes.

En-Vision (Enhanced Vision) provides non-contact measurements for detecting buried defects like dislocations, oxygen precipitates, or stacking faults, which are not visible through optical inspection. It significantly improves buried defect detection within IC Fabs, offering a more than 100× enhancement compared to traditional methods like X-TEM or SECCO etching.
En-Vision offers a wide dynamic range for defect size (15 nm to sub-micron) and density (E6 – E 10 /cm3). It detects radiative emission (photoluminescence) from buried defects, allowing the detection of defect sizes much smaller than what optical optics can resolve.

The Polarized Stress Imaging (PSI) technology is suitable for classifying Si wafers or Si slugs before wafer based on measurement of IR light depolarization.

The maximum magnification achievable with a conventional optical microscope is limited to about 800-1000× due to the properties of light. For higher magnification, Scanning Electron Microscopes (SEMs) are typically used, with Transmission Electron Microscopes (TEMs) providing the highest magnification, even down to single atoms.
However, the Scanning Probe Microscope (SPM) serves a unique purpose for several reasons:
1.Preservation of Samples: TEMs require thin slicing of samples, often damaging them in the process. SPM, on the other hand, images surface structures at the atomic level without harming the sample.
2.Three-Dimensional Imaging: SPM microscopes provide three-dimensional imaging, even when evaluating two-dimensional information. In contrast, electron microscopes struggle to investigate a sample's surface structure effectively.
3.Non-Vacuum Operation: SPM operates in ambient conditions, unlike electron and optical microscopes that require a vacuum environment.
4.Measurement of Physical Properties: SPM can measure various physical properties, including electrical properties (e.g., Kelvin probe force microscopy, KPM/KPFM) and magnetic properties (Magnetic force microscopy, MFM). This versatility sets it apart from other microscopes.

Photo-modulated Reflectivity Measurement (PMR) is a technology used for monitoring the implantation dose of as-implanted pre-annealed production wafers. This method involves illuminating the wafer with two different lasers (Generation laser - λ1, Probe laser - λ2) with distinct wavelengths. The Generation laser is modulated while the Probe laser remains constant. The reflected light from the wafer is analyzed to detect changes in reflectance, which form the PMR signal sensitive to implant damage and carrier concentration.

The PMR operation relies on a pattern recognition system, ensuring the proper placement and orientation of the wafer. The Generation laser creates excess carriers and optimizes heating in areas with significant damage. The excess carriers and heat gradient result in an index of refraction gradient. The Probe laser uses this gradient or surface heat to determine the dose level or junction depth. The Generation laser operates at 2 kHz (quasi-static), resulting in a high signal-to-noise ratio, and enhanced stability in laser light intensities is achieved with a new beam sampler.
The PMR signal can be fitted to dose (1/cm2), showing a functional relation between implantation dose and the PMR signal, allowing for dose determination in production samples. Dose sensitivity varies with the implantation species used. Additionally, sensitivity to other implantation parameters, such as implantation energy and temperature, can be calculated using the same principle.

The combination of the ion implant process and the process to anneal implants is usually monitored by measuring the sheet resistance of the implanted layer. The sheet resistance varies with dose, energy, and the amount of implanted species that has become electrically active. It is the sheet resistance that ultimately determines the device performance. Thus, measuring sheet resistance is an excellent way to monitor everything associated with an implant process.
The basic idea of the JPV method is the light excitation of the np or pn layer structure, and the pick-up of the resulting junction photovoltage by a capacitive probe. The detected potential is determined by the sheet resistance of the implanted layer, capacitance of junction and resistance through over the diode.Semilab offers JPV technology to make non-contact, high resolution fast maps of sheet resistance.
MEASUREMENT THEORY:
The sample is illuminated by chopped LED light, which generates electrons and holes in the substrate layer. The generated charge carriers diffuse to the junction and the electric field located in the junction separates them. The result of the separation is the change in the junction voltage. This voltage change spread laterally in the implanted layer and the attenuation depends on the sheet resistance, junction capacitance, resistance of the junction and chopping frequency of the LED.
The potential change is detected by a capacitive sensor in order to evaluate the JPV signal, as a function of the frequency of the emitted light.
Based on the evaluation, the sheet resistance (Rs), capacitance of junction (Cd) and the resistance of the diode (Rd) can be calculated.
The junction leakage current is directly connected to the Rd by the following equation:
I_L = kt/q/R_d

Ellipsometry Porosimetry (EP) is a cutting-edge technology that measures changes in optical properties and film thickness during the adsorption and desorption of volatile substances. It offers unique advantages:

- EP can measure the porosity of extremely thin films, as thin as 10nm, with remarkable precision and speed.
- Unlike traditional Porosimeters, it excels at accurately determining pore size and distribution in thin films.
- EP employs spectroscopic ellipsometry (SE) and holds an exclusive patent from IMEC, licensed to Semilab.
- It works under both atmospheric pressure (EPA) and reduced pressure (EP) conditions.
- EP can assess both micro and meso porosity, covering a range of layers from 10nm to several µm.
- No sample preparation or film scratching is needed, ensuring reproducibility and speed.
- EP finds applications in Silicon-based technology, Photovoltaics, organic electronics, and the SolGel coating industry.

In summary, Ellipsometry Porosimetry is a cutting-edge tool for precisely analyzing porosity in thin films, offering versatility, accuracy, and efficiency for various industries.

Semilab SDI's FAaST systems are cutting-edge non-contact electrical metrology tools used in semiconductor device and material manufacturing. These systems employ non-contact surface potential probing techniques, along with illumination and surface charging methods, to precisely measure various parameters of semiconductor wafers, dielectrics, and interfaces. This advanced technology offers exceptional accuracy and efficiency while eliminating the need for dedicated test devices, saving both time and cost.
One of the key features is the compact SPV sensor integrated into the WT-2000 multi-metrology platform, which enables a comprehensive analysis of silicon wafer electrical quality.
Semilab SDI's patented digital SPV technique, featured in the FAaST systems, is the global leader for non-destructive measurements of heavy metal contamination in silicon. It provides rapid and reliable measurements of minority carrier diffusion length, particularly at low injection levels. Combined with unique activation methods, it offers unparalleled sensitivity in identifying contaminants like Cu and Fe.
The small signal ac-surface photovoltage (SPV) minority carrier diffusion length measurement plays a crucial role in detecting iron contamination and micro defects in silicon wafers. It is used for evaluating crystal growth, ingot-to-wafer processing, wafer cleaning, monitoring iron contamination during semiconductor processing steps, and requalifying processing tools after maintenance.
In ac-SPV metrology, multi-wavelength light generates excess minority carriers beneath the surface, leading to diffusion and recombination. The final profile depends on the minority carrier diffusion length, which is a sensitive indicator of recombination centers like Fe, Cu, and others. Contamination monitoring involves measuring the diffusion length. By selectively altering the recombination activity of contaminants through specific treatments such as strong illumination or thermal processes, it's possible to determine the contributions of different contaminants like Fe, Cu, and others to the overall diffusion length.

Lifetime is a characteristic of semiconductor materials, representing the average duration that excess carriers exist in the material before recombining to reach equilibrium. It's also referred to as "minority carrier lifetime," "carrier lifetime," and "recombination lifetime." In a perfect crystal lattice without contamination, the semiconductor material has a long lifetime. However, any imperfections in the semiconductor material or contamination can reduce this lifetime. Therefore, monitoring lifetime is an excellent method for detecting contamination.
The most common technique for measuring lifetime is known as microwave Photoconductance Decay (µ-PCD).
µ-PCD relies on generating excess carriers through laser pulses, which affect the material's conductivity and subsequently microwave reflectivity. After the illumination, the conductivity decreases due to recombination, and this decay can be monitored by measuring microwave reflectivity over time. Lifetime is determined from the recorded decay transient. To achieve the best results, surface recombination needs to be eliminated through passivation. Semilab offers a specialized treatment chamber to achieve an optimal surface without the use of wet chemicals.