Abstract: A metal–insulator–silicon (MIS) capacitor with hemi-spherical grained poly atomic layer deposition (ALD) deposited Al2O3 and multi-layered chemical vapor deposition (CVD) TiN structure is fabricated. The impactof the deposition process and post treatment condition on the MIS capacitor’s time-dependent dielectric breakdown(TDDB) performance is also studied. With an optimized process, it is confirmed by Auger electron spectroscopy andsecondary ion mass spectrometry analysis that the Al(CH3)3/O3-based ALD Al2O3 dielectric film is carbon free andthe hydrogen content is as low as 9 × 10¹⁹ cm^-3. The top electrode TiN is obtained by multi-layered TiCl4/NH3 CVD deposited TiN followed by 120 s post NH3 treatment after each layer. This has higher diffusion barrier in preventingimpurity diffusion through TiN into the Al2O3 dielectric due to its smaller grain size. As shown in energy dispersive X-ray analysis, there is no chlorine residue in the MIS capacitor structure. The leakage current of the capacitor islower than 1 × 10^-12 A/cm² . No early failures under stress conditions are found in its TDDB test. The novel MIS capacitor is proven to have excellent reliability for advanced DRAM technology.

Key words: atomic layer deposition,  Al2O3, multi-layer TiN,  early failure, metal insulator silicon capacitors,  TDDB