Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 31: Poster: Nitrides

HL 31.10: Poster

Monday, March 31, 2014, 17:00–20:00, P2

MOVPE growth of group III-Nitrides on ruthenium coated silicon and sapphire substrates — •Silvio Neugebauer, Armin Dadgar, Jürgen Bläsing, Peter Veit, and Alois Krost — Institute of Experimental Physics, Otto-von- Guericke-University Magdeburg, Germany

We present results on MOVPE growth of group III-Nitrides on ruthenium coated sapphire and high index silicon substrates. The growth on high index silicon substrates is a promising way for achieving semi-polar GaN and hence a possibility to overcome the spontaneous and piezoelectric polarization field in conventionally grown c-axis devices. Unfortunately, the received GaN c-axis tilt angle with respect to the surface normal is a function of AlN seed layer thickness for a given high index silicon substrate. Higher tilt angles were achieved for thinner AlN seed layers with the drawback of an increased chance of melt-back etching. Therefore we investigated the application of a ruthenium layer deposited on the silicon substrate serving the purposes of a higher GaN c-axis tilt angle and reduced melt-back etching. On the other hand the deposition of ruthenium on sapphire substrates seems to be quite promising for the growth of III-Nitrides. The lattice mismatch of ruthenium compared to sapphire is as small as -1.5% and -1.1% along the a- and c-direction respectively. This is an excellent requirement for the epitaxial growth of film bulk acoustic wave resonators, which essentially consists of a piezoelectric thin film in a matrix of two electrodes. Unfortunately the growth of III-Nitrides on ruthenium is quite challenging. The possibilities and limitations are discussed.