Abstract:
Methods for forming openings in damascene structures, such as dual damascene structures are provided, using plug materials having varied etching rates. In one embodiment, a semiconductor substrate is provided with a low-k material layer formed thereabove, the low-k material layer having an upper surface and at least one via opening formed therethrough. A first plug material layer is formed over the low-k material layer and filled in the via opening, the first plug material layer having a first etching rate. The first plug material layer is etched back to form a first plug partially filling the via opening. A second plug material layer is formed over the low-k material layer and the first plug. The second plug material layer is etched back to form a second plug partially below the upper surface of the low-k material layer, the second plug material layer having a second etching rate higher than the first etching rate.
Abstract:
A cyanine dye for using in high density optical disc recording medium, having the following structure: ##STR1## wherein R represents 4-methoxycarbonyl benzyl group, X.sup.- represents an acid anion, and n represents an integer of 1 or 2. This cyanine dye is suitable for use as a .lambda.=450 nm.about.650 nm visible light-absorbing organic dye useful as a high density optical disc recording medium.
Abstract:
Methods for forming openings in damascene structures, such as dual damascene structures are provided, using plug materials having varied etching rates. In one embodiment, a semiconductor substrate is provided with a low-k material layer formed thereabove, the low-k material layer having an upper surface and at least one via opening formed therethrough. A first plug material layer is formed over the low-k material layer and filled in the via opening, the first plug material layer having a first etching rate. The first plug material layer is etched back to form a first plug partially filling the via opening. A second plug material layer is formed over the low-k material layer and the first plug. The second plug material layer is etched back to form a second plug partially below the upper surface of the low-k material layer, the second plug material layer having a second etching rate higher than the first etching rate.