| 摘要 |
<p>Processes for the addition or removal of a layer or region from a workpiece (14) material by contact with a process gas, in the manufacture of a microstructure, are enhanced by the use of a recirculation of the process gas. Recirculation is effected by a pump (18) that has no sliding or abrading parts that contact the process gas nor any wet (such as oil) seals or purge gas in the pump (18). Improved processing can be achieved by a process chamber (15) that contains a baffle (16), a perforated plate (17), or both, appropriately situated in the chamber (15) to deflect the incoming process gas and distribute it over the workpiece (14) surface. In certain embodiments, a diluent gas is added to the recirculation loop (36) and continuously recirculated therein, followed by the bleeding of the process gas (such as an etchant gas) into the recirculation loop (36). Also, cooling of the process gas, etching chamber (15) and/or sample platen can aid the etching process. The method is particularly useful for adding to or removing material from a sample (14) of microscopic dimensions.</p> |
