The performance of a capacitance-wire wave recorder
A capacitanoe-wire wave recorder circuit was used in conjunction with a p.t»f,e. wire probe to establish what errors are associated with using such a system for the measurement of small waves. In the experiments the probe was moved relative to the water, rather than vico versa and both photographic and electrical methods were employed to investigate the errors introduced by the meniscus, the wetting of the wire and the effects of wire thickness on the wave shapes. The electrical methods involved accurate recording of the probe movement by means of a linear potentiometer and a comparison of this movement with the wave form produced from the circuit measuring the chasige in capacitance of the probe caused by its movement in the water. The effects of increasing the operation! frequency of the recording circuit was also investigated.
Determination of the profiles of water waves
Tlw tvqmitor tjpc depth gayqe, dest'rihc~rl in //lis pq)pr, record the longitudinal proliles ancl cross-zectinns or undular faci/itntes n('cu/'n/i7 rei~~rdings (I/ t/7~ profi/rs o/ //ITPP surgc w;ivcs produced in ii prismoidnl channel. Thcsc waves r/itliPnsiona/ li'(1ter li'fmJLs propn,qo/er/ in prisnroir/n/ o/)en are produced when il sudden sustiiincd quontity or water is i~/iantir/s. The circuitry, priticip/e ant/ cnlihrotion of' //if, discharged into the ch;inncl. which contains an initial level gni/~~:~ nre out/ined, ii*it/i pnrtic.u/nr rqfirenc-r 10 //re of still water. The wave cross-scction is obtained by comnt1i-an~age.r <! f ' usinK srnnriurd indusrricd equipnretrr. piling the records from it number of probes on and offset
Bevel RIE application to reduce defectivity in copper BEOL processing
Bevel etch used during wafer fabrication for semiconductor devices is discussed. In this case, the bevel etch process was utilized in middle of the line processing (MOL) to reduce back end of line (BEOL) defectivity. Tungsten and titanium nitride films, from the formation of contacts to the transistors, extend into the bevel region of the wafer and have been shown to initiate arcing. This can spread foreign material defects on the front side of the wafer in various BEOL post processing steps including subsequent reactive ion etching, SEM metrology and film depositions. The bevel etch tool confines a plasma etch to the outer edge of the front side of the wafer (which can be individually adjusted) and can remove dielectric, organic and Ti/TiN/W films using a fluorine based chemistry.