Batch Atomic Layer Deposition of HfO2 and ZrO2 Films Using Cyclopentadienyl Precursors

Abstract

Thermal ALD deposition of ZrO2 and HfO2 films has been performed in the ASM A412(TM) 300mm vertical furnace using bis-cyclopentadienyl precursors. Due to the long precursor residence time and high surface area to be covered in a batch reactor, the thermal stability and volatility of the precursor is of critical importance. Evaluation of the thermal stability of the precursor was done by depositing on high surface area silica powder and then NMR studies were employed to evaluate precursor reactivity. The first deposition studies were in single wafer reactors to assess the viability for scale-up to batch processing. The deposition studies performed have shown that the family of bis-cyclopentadienyl precursors has demonstrated sufficient thermal stability to successfully achieve ALD films which meet deposition requirements in batch reactors for capacitor dielectrics in memory devices.