| AVS 63rd International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS-MoA |
| Session: | Advanced BEOL/Interconnect Etching |
| Presenter: | Michelle Paquette, University of Missouri-Kansas City |
| Authors: | M.M. Paquette, University of Missouri-Kansas City S. Dhungana, University of Missouri-Kansas City B.J. Nordell, University of Missouri-Kansas City A.N. Caruso, University of Missouri-Kansas City W.A. Lanford, University at Albany G. Chollon, Universite de Bordeaux, France C. Pallier, Universite de Bordeaux, France F. Teyssandier, Universite de Bordeaux, France K. Scharfenberger, Intel Corporation D. Jacob, Intel Corporation S.W. King, Intel Corporation |
| Correspondent: | Click to Email |
To continue the aggressive scaling of integrated circuit feature size demanded by current and future technology nodes, the microelectronics industry has turned to multiple patterning techniques to overcome lithography limitations. These techniques use a series of lithography and etch pattern transfer steps that require a variety of photoresist, hardmask, spacer, etch stop, and other specialized layers. These various pattern transfer materials can be categorized into ‘colors,’ where each color can be uniquely processed. As multiple patterning designs become increasingly complex, a number of different patterning materials with near-perfect etch selectivity will be needed, for which the current selection of materials will not suffice. Many previous etch studies have investigated the effects of plasma conditions on etch rates for common classes of metal and dielectric materials, but fewer have looked at the dependence of etch rates on material composition within a given class, and fewer still have analyzed the relative etch rates of multiple material classes and compositions under identical treatment conditions. We have surveyed etch rates for a wide range (>300) of samples using two common fluorinated etches traditionally used to pattern silicon-oxide-based (CHF3) and silicon-nitride-based dielectrics (CF4/O2). These samples were drawn from material classes falling within the common Si-C-O-N-H composition space (e.g., SiOx:H, SiOxCy:H, SiNxCy:H), as well as classes not traditionally considered for patterning applications including hi-k dielectrics (e.g., Al2O3, HfO2) and boron-rich solids (e.g., BN:H, BP:H, BC:H). Surveying such a wide range of materials with varying densities and chemical stoichiometries has allowed us to look at both the effect of composition on etch rates as well as the relative etch rates between classes. From this information, we are able to propose materials that may serve as additional etch colors, drawn from within the classes studied, and by extrapolating the observed trends to different composition spaces.