The N2 purge was 10 s after the TEG and 6 s after the NH3 plasma. In ABC-pulsed experiments, the B-pulse was either Ar-plasma (100 sccm with 2000 W plasma power), H2 gas (50 sccm H2 mixed with 100 sccm Ar), or H2 plasma (50 sccm H2 mixed with 100 sccm Ar and 2000 W plasma power). A 2 s N2 purge was added after the B-pulse. Also, experiments were carried out using identical growth conditions except that the plasma during the NH3 step was turned off to study a thermal NH3 pulse.