Oxidation inhibiting properties of Si3N4-layers produced by ion implantation

The implantation of nitrogen into silicon to produce Si₃N₄ layers was investigated to find an alternative to CVD-Si₃N₄ layers used in ISOPLANAR-and LOCOS-technology. The technological properties of the implanted Si₃N₄ layers in respect to oxidation inhibition and etching are comparable or superior to CVD-Si₃N₄ layers. The implanted layers are more resistent against oxidation for nitrogen doses of 2.4×10¹⁷ cm⁻² at 30keV. The etching behavior is comparable for both types of Si₃N₄-layers. In the implanted layers no pinholes are found and threre is no formation of a bird's beak, as is well known in the case of CVD-nitride.