Evaluation of Thermal Versus Plasma-Assisted ALD Al2O3 as Passivation for InAlN/AlN/GaN HEMTs
Artikel i vetenskaplig tidskrift, 2015

Al2O3 films deposited by thermal and plasma-assisted atomic layer deposition (ALD) were evaluated as passivation layers for InAlN/AlN/GaN HEMTs. As a reference, a comparison was made with the more conventional plasma enhanced chemical vapor deposition deposited SiNx passivation. The difference in sheet charge density, threshold voltage, f(T) and f(max) was moderate for the three samples. The gate leakage current differed by several orders of magnitude, in favor of Al2O3 passivation, regardless of the deposition method. Severe current slump was measured for the HEMT passivated by thermal ALD, whereas near-dispersion free operation was observed for the HEMT passivated by plasma-assisted ALD. This had a direct impact on the microwave output power. Large-signal measurements at 3 GHz revealed that HEMTs with Al2O3 passivation exhibited 77% higher output power using plasma-assisted ALD compared with thermal ALD.

GaN HEMT

ALD

InAlN

passivation

Al2O3

Författare

Anna Malmros

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

P. Gamarra

Thales Research and Technology

M. A. di Forte-Poisson

Thales Research and Technology

Hans Hjelmgren

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

C. Lacam

Thales Research and Technology

Mattias Thorsell

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

M. Tordjman

Thales Research and Technology

R. Aubry

Thales Research and Technology

Niklas Rorsman

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

IEEE Electron Device Letters

0741-3106 (ISSN)

Vol. 36 235-237

Styrkeområden

Nanovetenskap och nanoteknik

Ämneskategorier

Annan elektroteknik och elektronik

Den kondenserade materiens fysik

DOI

10.1109/LED.2015.2394455