Preparation of epitaxial graphene surfaces for atomic layer deposition of dielectrics

摘要

Processes for preparation of an epitaxial graphene surface to make it suitable for deposition of high-κ oxide-based dielectric compounds such as Al2O3, HfO2, TaO5, or TiO2 are provided. A first process combines ex situ wet chemistry conditioning of an epitaxially grown graphene sample with an in situ pulsing sequence in the ALD reactor. A second process combines ex situ dry chemistry conditioning of the epitaxially grown graphene sample with the in situ pulsing sequence.

主权项

1. A process for functionalizing a surface of an epitaxial graphene sample (EG sample) for atomic layer deposition (ALD) of a dielectric in an ALD reactor, the process comprising:
(1) subjecting the EG sample to an ex situ functionalization step, the ex situ functionalization step comprising:
(a) immersing the EG sample in an acid solution for several seconds;(b) removing the EG sample from the acid solution and rinsing with H2O for several seconds; and(c) immersing the rinsed EG sample in a warm SC1 solution for several minutes to form an OH-terminated surface on the EG sample, the OH-terminated surface being capable of nucleation of dielectrics thereon, wherein the warm SC1 solution comprises NH4OH, H2O2, and deionized water in a 1:1:5 ratio, respectively, and wherein the SC1 solution is at about 80-110° C.; and (2) subjecting the EG sample having an OH-terminated surface to an in situ treatment cycle, the in situ treatment cycle comprising a plurality of H2O pulses inside the ALD reactor, each of the plurality of H2O pulses being separated only by a corresponding purge step; wherein the functionalized surface of the EG sample is configured for the disposition of a smooth and conformal dielectric layer thereon.