Methods of depositing a silicon nitride film

A method of depositing a silicon nitride film, the method comprising:

• loading a substrate into a reactor;
• and
• conducting one or more atomic layer deposition (ALD) cycles, at least one of the cycles comprising steps of:
• supplying a halo-silane to the reactor;
• supplying a purge gas to the reactor after supplying the silicon source gas;
• supplying ammonia gas to the reactor after supplying the purge gas;
• and
• applying radio frequency (RF) power to the reactor to generate ammonia plasma after supplying the silicon source gas and the purge gas without supplying the silicon source gas.

An apparatus, comprising:

• a substrate;
• a silicon nitride film formed over the substrate, wherein the silicon nitride film is formed by conducting one or more deposition cycles, at least one of the cycles comprising steps of:
• supplying a chlorosilane gas to the reactor;
• supplying a purge gas to the reactor;
• and
• providing ammonia plasma to the reactor after supplying the silicon source gas and the purge gas without supplying the silicon source gas,
• wherein the silicon nitride film contains chlorine atoms in an amount less than about 1.2 atomic %.