Fermi-Level Tuning of G-Doped Layers.

Avto Tavkhelidze,Larissa Jangidze,Amiran Bibilashvili,Nima E Gorji

doi:10.3390/nano11020505

Avto Tavkhelidze, Larissa Jangidze + Show 2 more

Open Access

https://doi.org/10.3390/nano11020505

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Journal: Nanomaterials	Publication Date: Feb 17, 2021
Citations: 21	License type: CC BY 4.0

Affiliation: Ilia State University, Dublin City University

Abstract

Recently, geometry-induced quantum effects were observed in periodic nanostructures. Nanograting (NG) geometry significantly affects the electronic, magnetic, and optical properties of semiconductor layers. Silicon NG layers exhibit geometry-induced doping. In this study, G-doped junctions were fabricated and characterized and the Fermi-level tuning of the G-doped layers by changing the NG depth was investigated. Samples with various indent depths were fabricated using laser interference lithography and a consecutive series of reactive ion etching. Four adjacent areas with NG depths of 10, 20, 30, and 40 nm were prepared on the same chip. A Kelvin probe was used to map the work function and determine the Fermi level of the samples. The G-doping-induced Fermi-level increase was recorded for eight sample sets cut separately from p-, n-, p+-, and n+-type silicon substrates. The maximum increase in the Fermi level was observed at a10 nm depth, and this decreased with increasing indent depth in the p- and n-type substrates. Particularly, this reduction was more pronounced in the p-type substrates. However, the Fermi-level increase in the n+- and p+-type substrates was negligible. The obtained results are explained using the G-doping theory and G-doped layer formation mechanism introduced in previous works.

Highlights

The eV riseinin electron concentration from ≈3 × 1015 cm−3 to ≈ 1 × 1018 cm−3. These results indicate that the G-doping level in both samples was sufficiently high to change the substrate type from p to p+ or from n to n+
In this study the G-doping level dependence on the nanotechnology havenanogratings allowed the (NGs) depth was investigated in p, n, p+ - and n+ -type Si substrates
The measurements revealed that the G-doping level reduced with increasing indent depth in the range from 10 to 40 nm for both the p- and n-type substrate samples

Summary

Introduction

The latest developments in nanotechnology have allowed the fabrication of lowThe latest developments in nanotechnology havenanogratings allowed the (NGs).fabrication of low-didimensional periodic nanostructures [1,2,3], includingImposed perimensional periodic nanostructures [1,2,3], including nanogratings (NGs).Imposed periodic nanostructures such as NG layers are known to significantly affect the electronic [4,5], odic nanostructures such as NG layers are known to significantly affect the electronic thermoelectric [6,7], optical [8,9], electron emission [10,11], and magnetic [12,13] properties [4,5], thermoelectric [6,7],[8,9], electroncomparable emission [10,11], magnetic [12,13]of semiconductors when theopticalNG depth becomes to the deandBroglie wavelength.properties of semiconductors when the depth becomes comparable to the de BroglieThis can be attributed to the special boundary conditions enforced by the NG on the wave wavelength.can be they attributed the special boundary conditions enforced bydensity. Imposed perimensional periodic nanostructures [1,2,3], including nanogratings (NGs). Imposed periodic nanostructures such as NG layers are known to significantly affect the electronic [4,5], odic nanostructures such as NG layers are known to significantly affect the electronic thermoelectric [6,7], optical [8,9], electron emission [10,11], and magnetic [12,13] properties [4,5], thermoelectric [6,7],. Properties of semiconductors when the depth becomes comparable to the de Broglie This can be attributed to the special boundary conditions enforced by the NG on the wave wavelength.

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