| AVS 63rd International Symposium & Exhibition | |
| Electronic Materials and Photonics | Friday Sessions |
| Session EM-FrM |
| Session: | Late Breaking News on Electronic Materials and Devices |
| Presenter: | Karthik Sridhara, Texas A&M University |
| Authors: | K. Sridhara, Texas A&M University B.N. Feigelson, US Naval Research Laboratory J.K. Hite, US Naval Research Laboratory V. Anderson, US Naval Research Laboratory A. Nath, US Naval Research Laboratory F. Kub, US Naval Research Laboratory L.O. Nyakiti, Texas A&M University Galveston |
| Correspondent: | Click to Email |
Chemical vapor deposition (CVD) method of growth of hexagonal boron nitride (h-BN) has been demonstrated on various transition metal substrates such as Ni, Pt, Au and Ag. Of these metals, polycrystalline Cu is by far the most frequently used substrate for CVD growth of h-BN. Despite being extensively studied, issues still persist with Cu, including a high density of nucleation sites where the imperfections in surface morphology act as potential nucleation sites. Recently, Cu-Ni alloys have been reported for the growth of controllable monolayer h-BN with fewer nucleation sites [1]. Despite the promise, there are still questions of optimal Ni concentration and the morphology of Cu-Ni alloys.
In this work, we prepare Cu-Ni alloys by electroplating Ni on high purity (99.98%) polycrystalline Cu foils (25 μm thickness). Four different weight percents of Ni (10, 15, 20 and 25 wt%) are electroplated onto Cu. The electroplated foils are then thermally annealed at 1030°C for 3 hours in an H2 environment, during which time the Ni diffuses into the Cu foils. We then grow h-BN on these Cu-Ni alloys, with high purity (~99.98%) Cu foils acting as our control samples. The growth uses borazane as the precursor at 1030°C with H2 and N2 as carrier gases. FTIR and scanning electron microscope (SEM) are used to confirm and assess the growth of h-BN on the samples. Energy dispersive spectroscopy (EDS) mapping is employed to cross-check the Ni percentage in Cu. From the preliminary results, we observe that with increasing Ni concentration there is an increase in surface roughness with the existence of atomic step edges and various morphological irregularities. Initial FTIR results show that with increasing amount of Ni in the Cu foil, we see a gradual increase in the amount (proportional to the FTIR peak intensity) of h-BN grown where the amount is proportional to the h-BN film effective thickness on the substrate [2]. We see the lowest amount of h-BN is on Cu, while the highest is on Cu0.75Ni0.25 foils. The growth kinetics of h-BN on Cu-Ni alloys will be discussed.
References:
[1] G. Lu, T. Wu, Q. Yuan, H. Wang, H. Wang, F. Ding , "Synthesis of large single-crystal hexagonal boron nitride grains on Cu-Ni alloy," vol. 6, p. 6160, 2015.
[2] B. N. Feigelson, V. M. Bermudez, J. K. Hite, Z. R. Robinson, V. D. Wheeler, K. Sridhara , "Growth and spectroscopic characterization of monolayer and few-layer hexagonal boron nitride on metal substrates," vol. 7, pp. 3694-3702, 2015.