High resolution Laplace Deep Level Transient Spectroscopy studies of shallow and deep levels in n-GaN

The Sliding-Aperture Transform and Its Applicability to Deep-Level Transient Spectroscopy

“…Although relatively simple for a single defect, the challenge is to resolve the signatures of multiple defects, whose concentration, type, and ionization parameters are unknown [2][3][4][5][6][7][23][24][25][26]. In traditional boxcar-based, temperature-swept DLTS, two neighboring peaks can be distinguished if their emission rates differ by at least ~8 times [6].…”

“…In traditional boxcar-based, temperature-swept DLTS, two neighboring peaks can be distinguished if their emission rates differ by at least ~8 times [6]. Other, more recent DLTS analysis techniques utilize the Laplace transform (L-DLTS) or Fourier transform (deep-level Fourier spectroscopy) to improve signal acquisition and rate extraction to improve emitter distinguishability [6,7,23]. Both techniques are constanttemperature approaches, such as the SLAP technique, allowing for unlimited signal averaging for improved signal-to-noise ratio.…”

“…As will be shown, the SLAP technique also provides both minority and majority carrier defect information from a single transient. In all cases, a constant-temperature approach is used for more precise determination of defect parameters through signal averaging, with a signal-to-noise ratio of at least 1000 required for Laplace DLTS to provide better rate resolution than offered by the traditional double-boxcar DLTS technique [23].…”

“…The strength of the SLAP approach to transient analysis is the ability to use Equation ( 10) and a simple curve-fitting algorithm to curve-fit a multipeak spectrum based on an integer number of defects. This removes user intervention from the process of rate and peak height determination and is not only the strength of this work but is prominent attribute for both L-DLTS and deep-level Fourier spectroscopy [6,7,23]. SLAP offers another means of characterizing defect spectrum through the sequential use of Equation (10), first under the assumption of a single defect (i.e., i = 1, k = 1), followed by the introduction of more defect species (i.e., k > 1).…”