Sentence:  Two other materials-based approaches may be employed in the present invention. One is to use highly doped glass (with boron or phosphorus) or plasma nitride (otherwise known as <WSD>nitrox</WSD>) as the inter-metal layer insulator. 
Meaning of the word marked with <WSD> tags:  An industrial process for case hardening (imparting greater surface hardness to) metal objects, involving nitrocarburizing (the diffusion of carbon and nitrogen into the metal) followed by oxidation.