摘要:
A method for planarizing a layer (18) begins by forming a layer (18) over a wafer having a substrate (12). Layer (18) has a surface topography which is not planar. A layer of material (20) is formed over the layer (18). The layer of material (20) has a surface which is more planar than the surface of layer (18). The surface of material (20) is transferred into the layer (18) by etching the layer (18) and the material (20) at approximately the same etch rate. The same etch rate is achieved by monitoring one of either the surface of the wafer or the etch environment of an etch system chamber. A computer-controlled feedback path alters an etch chemistry or etch environment to maintain the etch rates within an etch rate tolerance which is also referred to as a process window. By monitoring and altering the etch environment and/or the etch chemistry to maintain a process window, an optimal planar surface is achieved for layer (18).
摘要:
A chemical-mechanical-polishing (CMP) process in which a metal interconnect material (47) is polished to form a metal plug (48) includes the application of titanium to the surface of a polishing pad (14) of a polishing apparatus (10). Titanium metal is applied to the surface of the polishing pad (14) by either abrasively applying titanium by use of a titanium block (32) attached to a rotating disk (26), or by a titanium body (23, 25) integrated with a carrier ring (23). Alternatively, titanium can be applied by impregnating a felt layer (52) with titanium particles (56), or by adding titanium directly to the polishing slurry (50).
摘要:
Lactose having reproducible pH and a lowered ash level can be produced from lactose rich permeate resulting from the ultrafiltration of whey, by adding a small amount of a chelating agent such as a salt of ethylenediaminetetraacetic acid as, for instance, the disodium salt, the calcium disodium salt, or an alkali metal polyphosphate, as sodium hexametaphosphate to the lactose containing permeate prior to crystallization of the lactose.