Photo-Excited Desorption Analyzer PSD

Features
The Photo-Stimulated Desorption/Ionization (PSD) instrument is an analytical device that irradiates a sample with vacuum ultraviolet light (120–400 nm) and observes molecules desorbed from its outermost surface using a mass spectrometer.
By scanning the irradiation wavelength, differences in desorption components at each wavelength can be identified, enabling analysis of contaminants on the sample surface, the structure of the sample's outermost layer, and the effects of vacuum ultraviolet radiation on the sample.
Furthermore, utilizing the thermal assist function allows observation of photoexcited desorption phenomena at specified temperatures, aiding in the design of thermal and optical processes used in semiconductors, displays, solar cells, and other applications.

Load Lock Chamber Equipment

Load Lock Chamber Equipment
Like all our analytical instruments, it is equipped with a load lock chamber to enhance measurement efficiency and maintain a high vacuum environment.

Vacuum Ultraviolet Light Source
Laser-excited plasma generated from an Nd³⁺:YAG laser in argon gas produces light across a broad wavelength range from the vacuum ultraviolet to the visible spectrum. By irradiating the sample with monochromatic light collected after spectral separation by a diffraction grating, ionization occurs at each irradiation wavelength. Wavelength sweeping can be set to proceed either from long to short wavelengths or from short to long wavelengths.

Heat-Support Type
Photoexcited desorption induced by vacuum ultraviolet irradiation is promoted by increasing the temperature. By applying our TDS technology, we can perform vacuum ultraviolet irradiation while maintaining the sample at a constant temperature.

Configuration of the Photo-Detachment Analyzer

Configuration of the Photo-Detachment Analyzer

Configuration of the Photo-Detachment Analyzer
The photo-desorption analyzer consists of a vacuum ultraviolet light source unit that generates vacuum ultraviolet light and a measurement unit that detects components desorbed from the sample.

Vacuum ultraviolet light source
When an Nd³⁺:YAG laser is introduced into a light source chamber filled with argon gas, the argon gas becomes excited and plasma is generated. This laser-excited plasma emits light across a broad wavelength range extending from the vacuum ultraviolet to the visible region.
By irradiating the sample with monochromatic light spectroscopically separated by a diffraction grating, desorption at each irradiation wavelength is observed.
The available wavelengths are determined by the installed diffraction grating; this device standardizes wavelengths from 120 to 400 nm.

Load Lock Chamber
Load lock chambers are essential for achieving high measurement efficiency (high throughput) and high sensitivity.
Our load lock chamber and sample transfer mechanism enable rapid introduction of only the sample into the ultra-high vacuum analysis chamber.
Without a load lock chamber, the analysis chamber must be vented to atmosphere each time a sample is changed. Once vented, a large amount of atmospheric components (especially moisture) adsorb onto the analysis chamber, requiring a long time for sufficient evacuation.

Analysis chamber
Photoexcited desorption induced by vacuum ultraviolet irradiation is promoted by increasing the temperature. By applying our TDS technology, vacuum ultraviolet irradiation can be performed while maintaining the sample at a constant temperature.
The analysis chamber has a configuration equivalent to that of a thermal desorption analyzer. Samples can be heated while minimizing background level increases even in the high-temperature range. The spectroscopic chamber of the vacuum ultraviolet light source section and the analysis chamber of the measurement section are connected and separated by a MgF2 window flange.