Abstract: A method for etching contact openings into a polycide layer including a metal silicide layer and a polysilicon layer comprises providing a substrate that includes a polycide layer, forming a patterned photoresist mask, and etching with a series of plasmas. The etches include a silicide etch, a polycide etch including chlorine gas and nitrogen gas where the nitrogen flow rate is between 20% and about 30% of the sum of the nitrogen flow rate plus the chlorine flow rate, and a poly overetch. A polycide etch with a composition in the specified range will have a polycide selectivity greater than one.

Abstract: In a computer system, one or more ISA connector sockets is replaced by a connector structure which carries both ISA signals and local bus signals. The connector structure is arranged such that a standard ISA accessory card may be inserted, in which case only ISA signals are coupled to or from the card. "Local bus" accessory cards may also be designed for insertion into such a connector, and these cards may connect to one or more signal lines of the local bus either additionally or instead of connections made to the ISA bus. By physical or other means, ISA accessory cards are prevented from unintentional contact with connector contacts which are coupled to local bus signal lines. The connector structure may advantageously comprise an EISA-type connector socket.