Characteristics of RutheniumThin Films on SiO2 deposited by Remote Plasma Atomic Layer Deposition

Abstract

The nucleation behavior of ruthenium deposited by remote plasma atomic layer deposition using bis(ethylcyclopentadienyl)ruthenium as a precursor and ammonia (NH3) plasma as a reactant, is investigated on two different silicon dioxide (SiO2) substrates. These substrates are chemically deposited SiO2 and thermally grown SiO2. There were the difference in the surface polar component and the surface polar component on chemically deposited SiO2 is higher than that on thermally grown SiO2 in wet atmosphere. The deposition cycle to make continuous ruthenium film on chemically deposited SiO2 was 135 cycles and that on thermally grown SiO2 was 130 cycles. At the initial cycle (~30 cycle), the density of ruthenium clusters on chemically deposited SiO2 substrate and thermally deposited SiO2 were 2.97?1012 cm-2 and 1.98?1012 cm-2, respectively. This difference lead to faster formation (130 cycles) of continuous ruthenium film on chemically deposited SiO2 and the resistivity of ruthenium film on chemically deposited SiO2 was 30 % lower than that on thermally grown SiO2.