The DLTS method is an excellent technique to detect the electronic state (deep level) created by crystal defects with high sensitivity.
Since semiconductor materials are greatly affected by very small inherent impurities or lattice defects (crystal defects), defect evaluation is extremely important.In the DLTS method, by monitoring the dynamic process by which the carrier (e.g. electron) trapped in the deep level is emitted into the band (conduction band), through the transient changes in the junction capacitance of the sample, the parameters (energy levels, capture cross-section) and concentration value, spatial distribution etc. of the level can be known.
The Phystech (Germany) DLTS Measuring Device (FT1230 HERA-DLTS) sold by our company, in addition to being a highly sensitive measuring system essential in DLTS Measuring, is also a sophisticated measuring instrument equipped with software capable of dealing with defect evaluation for various semiconductor materials.
The FT1230, in addition to the basic DLTS measurement mode, has an ICTS (Isothermal Capacitance Transient Spectroscopy) mode for time domain measurement under fixed temperatures.As well, the FT1230 can meet the needs for optical DLTS / ICTS using optical pulses, CC mode (Constant Capacitance-DLTS), current mode DLTS / ICTS, and PITS (Photo-induced current Transient Spectroscopy) method, effective for measuring semi-insulating semiconductors and ultra-thin layers where the entire sample is depleted, and TSC method (Thermally Stimulated Current) etc.Current mode, and DLTS / ICTS measurement, are also applied to defect evaluation in three-terminal elements such as FET etc.
A specialized manufacturer of DLTS measuring devices from the University of Kassel, Germany.Currently, Phystech has succeeded in the development of the only digital system among all the DLTS systems available for sale, the world's most popular DLTS measurement system, The FT-1230 released in 2016, in comparison with competitive products, has the most diversified measurement modes, and is the only system capable of the scale necessary to meet requests from researchers to measure all kinds of materials.
|HERA-DLTS||Standard DLTS measurement
Digital DLTS measurement
Laplace DLTS measurement Comprised of the above three modes
|Possible measurements||C/V, I/V, C(t) Measurement
C/V, I/V, Implemented characteristics
Ideal coefficient of the Schottky
diode Oxide-film thickness etc. calculations possible
|DLTS Measurement Options||Fourier transform
Multi-exponential transient fit
ITS (Isothermal transient spectrum) signal deconvolution
Tempscan signal deconvolution
ITS data (one temperature)
Measurement of ITS at several temperatures
Data 2) and 3) Based on Arrhenius plot
【Plot 1】 "Period width scans" of different temperatures."Emission time constant" recalculated to "tau" X Axis (measurement signal)
【Plot 2】 Scan of plot 1 (including deconvoluted curve and estimated time constant; vertical line)
【Plot 3】 Arrhenius plot from data of Plot 1 without deconvolution option
【Plot 4】 Arrhenius plot using deconvolution data (Level 1, Level 2) displayed in Plot 2 Note the comparison of plot 3 without convolution data
Multi-exponential transient fits (Provencher discrete, excellent results)
Laplace transform (Provencher contin, a poor result for this transient)