Aluminum Doping by Low-Temperature Homoepitaxial Growth for Ni Ohmic Contacts to p-Type 4H-SiC

Bharat Krishnan; Siva Prasad Kotamraju; Galyna Melnychuk; Neil Merrett; Yaroslav Koshka

doi:10.4028/www.scientific.net/MSF.615-617.581

Paper Titles

Heat-Resistant Barrier Contacts Made on the Basis of TiB_x and ZrB_x to SiC and GaN
p.565

Nano-Electro-Structural Evolution of Ni-Si Ohmic Contacts to 3C-SiC
p.569

On the Formation of Ni-Based Ohmic Contacts to n-Type 4H-SiC
p.573

Phase Inhomogeneity and Electrical Characteristics of Nickel Silicide Schottky Contacts Formed on 4H-SiC
p.577

Aluminum Doping by Low-Temperature Homoepitaxial Growth for Ni Ohmic Contacts to p-Type 4H-SiC
p.581

Process Optimization for High Temperature SiC Lateral Devices
p.585

A Comprehensive Study of Hydrogen Etching on the Major SiC Polytypes and Crystal Orientations
p.589

HCl Etching Behavior on Low-Tilt-Angle and Step-Free 4H-SiC Surfaces
p.593

Comparison between Polishing Etching of On and Off-Axis C and Si-Faces of 4H-SiC Wafers
p.597

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Aluminum Doping by Low-Temperature Homoepitaxial Growth for Ni Ohmic Contacts to p-Type 4H-SiC

Abstract:

Low-temperature halo-carbon homoepitaxial growth is suitable for selective epitaxial growth of 4H-SiC using SiO2 mask. A possibility of achieving high values of doping in combination with the selective growth makes it an alternative to ion implantation for selective doping in SiC. In this work, TMA doping in situ during a blanket low-temperature epitaxial growth was utilized to produce heavily Al doped SiC layers for Ohmic contact formation to p-type SiC. Nearly featureless epilayer morphology with Al atomic concentration exceeding 3x1020 cm-3 was obtained after growth at 13000C with the growth rate of 1.5 µm/hr. Ni TLM contacts with a thin adhesion layer of Ti were formed. The as-deposited metal contacts were almost completely Ohmic even before annealing. The specific contact resistance of 2x10-2 Ohm-cm2 and 6x10-5 Ohms-cm2 was achieved without and with contact annealing respectively. The resistivity of the epitaxial layers better than 0.01 Ohm cm was measured for Al atomic concentration of 2.7x1020 cm-3.