Effect of wet KOH etching on structural properties of GaN nanowires grown by SAG-MBE

1.

Effect of wet KOH etching on structural properties of GaN
nanowires grown by SAG-MBE
Vera V.Lendyashova1,2, Konstantin P.Kotlyar3, Vladislav O.Gridchin1,5, Rodion R.Reznik4, Alexey I.Lihachev2, Ilya
P.Soshnikov1,2,5, George E.Cirlin1-5
1 Alferov
2 Ioffe
University, Khlopina 8/3, 194021 St. Petersburg, Russia
Institute, Polytechnicheskaya st. 26, 194021 St. Petersburg, Russia
3 Saint-Petersburg
4 ITMO
State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia
University, Kronverkskiy pr. 49, 197101 St. Petersburg, Russia
5 Institute
for Analytical Instrumentation RAS, Rizhsky 26, 190103, St-Petersburg, Russia

2.

Outline:
Motivation
Experiment:
• GaN NWs grown by SAG-MBE
• Selective etching using a KOH aqueous solution
Identification of NWs polarity
Impact of etching time
Conclusions
2

3.

Motivation:
*
**
light emitting diodes (LEDs)
sensors
transistors
solar cells
water-splitting cells
* Albert S. et al., Journal of Applied Physics 2013:113 pp. 114306
** Arafin S. et al., Journal of Nanophotonics 2013:7 pp. 074599
3

4.

Experiment: SAG-MBE growth
*
Scheme of SAG-MBE:
SiOx
SI (111)
SiO2 microspheres
photoresist
**
300 nm
SI (111)
Si
SI (111)
SiOx
MBE growth
1 um
GaN nanowires
SI (111)
* Dvoretckaia L. N. et al., Journal of Physics: Conference Series 2017:917 pp. 062062
** Dvoretckaia L. N. et al., Journal of Physics: Conference Series 2018:1124 pp. 022042
4

5.

*
NWs diameter, mm
Experiment: GaN NWs grown by SAG-MBE
NWs diameter on Si
NWs diameter on SiOx
0,4
0,3
0,2
0,1
0,0
815
820
825
Substrate temperature, °С
Ts = 815℃
Ts = 820℃
Ts = 825℃
NWs height, mm
4
NWs height on Si
NWs height on SiOx
3
2
1
0
815
820
825
Substrate temperature, °С
* Gridchin, V.O. et al. Tech. Phys. Lett. 46, 1080–1083 (2020)
5

6.

Experiment idea: KOH selective etching
*
**
* Stacia Keller et al 2014 Semicond. Sci. Technol. 29 113001 ** Weijie Chen et al 2015 J. of Crystal Growth 426 168-172
6

7.

Experiment: KOH selective etching
Scheme of experiment*:
Chemical reactions:
2