Abstract:
It is arranged such that the least common multiple of two numbers m and n of which one is prime to the other, is made as large as possible where the number m is the rotational speed (rpm) of a platen with a polishing pad affixed thereto and the number n is the rotational speed (rpm) of a carrier with a wafer mounted thereon. As a result of such arrangement, it is not until the platen completes m revolutions that a point on the polishing pad that comes into contact with a fixed point on the wafer returns to the original contact point with the fixed point at the start of polishing, and the resulting trajectory is therefore spread uniformly over the polishing pad. Each point on the wafer is brought into contact with most surface regions of the polishing pad, therefore preventing the wafer from undergoing deterioration in planarity uniformity due to a particular point on the wafer, on one hand, frequently coming into contact with low polishing-rate regions in the polishing pad and due to the other points on the wafer, on the other hand, less frequently coming into contact with the regions.
Abstract:
A slurry feeding apparatus includes closed slurry bottle, piping, wet nitrogen generator, wet nitrogen supply pipe, suction and spray nozzles, temperature regulator, flow rate control valves, slurry delivery pump and controller for controlling the operation and flow rate of the slurry delivery pump. While a wafer is being polished by a CMP polisher, the controller continuously operates the pump. On the other hand, while the polisher is idling, the controller starts and stops the pump intermittently at regular intervals. No stirrer like a propeller is inserted into the slurry bottle, but the slurry is stirred up by spraying the slurry through the spray nozzle.
Abstract:
A retainer board, holding a semiconductor wafer having a plurality of integrated circuit terminals for testing a semiconductor chip, is provided in confronting relation to a probe sheet having a plurality of probe terminals electrically connected to their corresponding integrated circuit terminals. An insulating substrate, having wiring electrically connected to the plural probe terminals, is provided on the probe sheet in opposed relation to the retainer board. An elastic member is interposed between the probe sheet and the insulating substrate. The retainer board and the probe sheet are brought into so closer relationship that each integrated circuit terminal of the semiconductor wafer held by the retainer board is electrically connected to its corresponding probe terminal of the probe sheet.
Abstract:
A method of fabricating a semiconductor memory device on a semiconductor substrate is disclosed. A gate electrode that becomes a word line, a bit line, and a charge-storage electrode are formed in a memory cell array region of a semiconductor substrate. A capacitor insulator layer and a plate electrode are formed in that order. Then, a BPSG film is formed in the memory cell array region and in the peripheral circuit region. A resist pattern is formed on the BPSG film, leaving the memory cell array region exposed. Using the resist pattern thus formed as a mask, an etching treatment is applied to remove an upper surface portion of the BPSG film lying within the memory cell array region by a given amount. After the resist pattern is removed, the BPSG film is heated in order that it reflows to planarize.