Characterization of deep-level defects in GaNAs/GaAs heterostructures grown by APMOVPE Cover

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Characterization of deep-level defects in GaNAs/GaAs heterostructures grown by APMOVPE

Materials Science-Poland

Volume 34 (2016): Issue 4 (December 2016)

By: Łukasz Gelczuk, Maria Dąbrowska-Szata, Beata Ściana, Damian Pucicki, Damian Radziewicz, Krzysztof Kopalko and Marek Tłaczała

Open Access

|Dec 2016

Figures & Tables

(a) Current-voltage and (b) capacitance-voltage characteristics recorded at 300 K for all studied samples. In the inset of (b) background doping concentration vs. depth profiles are plotted.

Low-temperature DLTS spectra obtained for the GaNxAs1−x/GaAs heterostructures with different nitrogen contents (x) at a reverse bias voltage (VR) of −2 V, a filling pulse voltage (VP) of 0 V, an emission rate window (en) of 20 s−1, and a filling pulse width (tp) of 50 s.

Exemplary Laplace DLTS spectra of the GaN0.016As0.984/GaAs structure, taken at 160 K, 180 K and 210 K for similar experimental conditions as those of conventional DLTS.

The Arrhenius plots of the peaks E1, E2, E3 depicted in Fig. 2 and Fig. 3 for the GaN0.016As0.984/GaAs structure. Crossed points correspond to conventional DLTS analysis and open points to Laplace DLTS analysis.

High-temperature DLTS spectra obtained for the GaNxAs1−x/GaAs heterostructures with different nitrogen contents (x). The inset shows corresponding LDLTS spectra recorded at 370 K.

The Arrhenius plots of the peak E4 for all studied samples. Crossed points correspond to conventional DLTS analysis and open points to Laplace DLTS analysis.

Activation energy Ea, apparent capture cross section σa and concentration NT obtained from the conventional DLTS and Laplace DLTS analysis of the trap E4 observed in the GaNxAs1−x/GaAs samples (x = 1_2 % to 2_7 %) in high-temperature spectra (>300 K)_ In the last column, possible identity of the trap has been proposed_

GaNAs/GaAs samples	E4 (EL2)					Possible identity
	DLTS			LDLTS
	N_T [cm⁻³]	E_a [eV]	σ_a [cm²]	E_a [eV]	σ_a [cm²]
1.2% N	2.3 × 10¹³	0.81	2.4 × 10⁻¹⁴	0.81	7.7 × 10⁻¹⁴	EL2^a–c
1.6 % N	2.0 × 10¹³	0.80	1.2 × 10⁻¹⁴	0.80	3.8 × 10⁻¹⁴
2.7 % N	2.6 × 10¹³	0.81	1.9 × 10⁻¹⁴	0.80	2.3 × 10⁻¹⁴

Concentration of the electron traps E1, E2 and E3 obtained from DLTS measurements of the GaNxAs1−x/GaAs samples (x = 1_2 % to 2_7 %)_

GaNAs/GaAs	E1 (N-related)	E2 (EL6)	E3 (EL3)
GaNAs/GaAs	NT [cm⁻³]	NT [cm⁻³]	NT [cm⁻³]
1.2 % N	1.3 × 10¹³	2.1 × 10¹³	1.1 × 10¹³
1.6 % N	1.8 × 10¹³	4.5 × 10¹³	4.2 × 10¹³
2.7 % N	1.6 × 10¹³	7.0 × 10¹³	4.5 × 10¹³

Activation energies (Ea) and apparent capture cross sections (σa) obtained from conventional DLTS and Laplace DLTS analysis of the traps E1, E2 and E3 observed in GaNxAs1−x/GaAs samples (x = 1_2 % to 2_7 %) in low-temperature spectra (<300 K)_ In the last column, possible identities of the traps have been made on the basis of comparison with activation energies of the defects observed in as-grown GaAs and GaNAs, as reported in the references given below_

Trap label	1.2 % N		GaNAs/GaAs 1.6 % N				2.7 % N		Possible identity
	DLTS		DLTS		LDLTS		DLTS
	E_a [eV]	σ_a [cm²]	E_a [eV]	σ_a [cm²]	E_a [eV]	σ_a [m²]	E_a [eV]	σ_a [cm²]
E1	0.24	8.8 × 10⁻¹⁸	0.21	2.9 × 10⁻¹⁸	0.20	3.4 × 10⁻¹⁸	0.15	2.1 × 10⁻¹⁸	N-related^a−d
E2	0.32	1.7 × 10⁻¹⁶	0.32	2.5 × 10⁻¹⁶	0.30	6.6 × 10⁻¹⁶	0.32	1.6 × 10⁻¹⁶	EL6^e−g
E3	0.49	3.9 × 10⁻¹³	0.49	3.2 × 10⁻¹⁴	0.48	1.5 × 10⁻¹⁴	0.49	5.2 × 10⁻¹⁴	EL3^f−h

DOI: https://doi.org/10.1515/msp-2016-0126 | Journal eISSN: 2083-134X | Journal ISSN: 2083-1331

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Language: English

Page range: 726 - 734

Submitted on: Dec 18, 2015

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Accepted on: Nov 2, 2016

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Published on: Dec 19, 2016

Published by: Wroclaw University of Science and Technology

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

dilute nitrides,

deep-level defects,

Related subjects:

Materials sciences,

Materials sciences, other,

Functional and smart materials,

Materials characterization and properties

© 2016 Łukasz Gelczuk, Maria Dąbrowska-Szata, Beata Ściana, Damian Pucicki, Damian Radziewicz, Krzysztof Kopalko, Marek Tłaczała, published by Wroclaw University of Science and Technology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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