Oxidation methods, which avoid consuming undesirably large amounts of surface material in SiSiGe heterostructure-based wafers, replace various intermediate CMOS thermal oxidation steps. The dynamic buffer management reduces buffer allocation for the current service period near the end of the current service period, and allocates the freed buffer space to one or more subsequent service periods before they begin. Advantageously, the cost of providing such access may be reduced compared to conventional approaches. The cover snap-attaches to the tray by means of at least one molded-in tab on the tray or cover which is received and frictionally retained by a corresponding well on the opposite element, thereby locating and securing the cover to the tray, and also locating and securing the central support panel between the tray and the cover. The objective function can be maximum mutual information, maximum likelihood training, minimum classification error training, or other functions known to those of skill in the art.