Hydrazine Gas for Low Temperature Nitrides
Hydrazine (H2NNH2) can be used as a low temperature thermal ALD nitride source. Next generation devices have low thermal budgets and high aspect ratio structures that create new challenges for nitride films. Ammonia is generally not reactive below 400C. Nitrogen created by plasma methods cannot uniformly coat the internal side walls of High Aspect Ratio structures and can cause surface damage.
Advantages of hydrazine gas
Hydrazine is more reactive than NH3, enabling thermal ALD at less than 300°C. Hydrazine gas can penetrate high aspect ratio structures to create uniform films because it does not require a line of sight, unlike plasma methods. Other variants of hydrazine such as hydrazine hydrate and methylhydrazine contain oxygen or carbon that can contaminate the film, leading to defects and poor electrical performance.
BRUTE vaporizer for hydrazine gas delivery
RASIRC BRUTE® Hydrazine delivers ultra-dry hydrazine gas into atomic layer deposition (ALD) processes. BRUTE Hydrazine combines anhydrous hydrazine and a low vapor pressure organic solvent that raises the flash point of the overall solution. A membrane delivery system within the BRUTE vaporizer is selective for hydrazine and not the organic solvent. This membrane also scavenges water and metal ions. Precursor vapor pressure is maintained at levels viable for ALD under vacuum with or without a carrier gas.