LITHOGRAPHIC APPLICATION OF DIAMOND-LIKE CARBON-FILMS

A combined laser-plasma-etching technique has been investigated for ut ilizing diamond-like carbon (DLC) films as resists in lithography. The technique is based on the selective enhancement of O-2 plasma etch ra tes of DLC films due to graphitization in the regions exposed to excim er laser radiation. The patterns delineated in the DLC resist by laser and oxygen plasma exposure have been transferred into the underlying silicon substrate by fluorocarbon reactive ion etching with (RIE) the patterned DLC film acting as an in situ mask. Using this scheme, space -line patterns 5 mu m wide were made on silicon substrates to demonstr ate the feasibility of the proposed laser-RIE process for semiconducto r patterning. The laser fluence required for graphitization is similar to 100 mJ cm(-2), the O-2 plasma etch rates of the graphitized region s are higher by a factor of similar to 3.5 and the contrast (gamma) fo r the DLC resist is 1.1. The use of DLC for submicron resolution warra nts further investigation.