Abstract: A process for backside chemical etching and polishing of substrates including the steps of protecting the front surface of the wafer, chemical etching, first dump rinse/spin dry, backside polishing, residue cleaning, second dump rinse/spin dry, and front surface protection removal. The process is generally intended to be used for semiconductor wafers, but it can also be used for processing other types of substrates such as GaAs, GaP, GaAlAs, GaAlP, ceramics, quartz, bonded silicon wafers, dielectric isolated wafers and substrates, etc.

Abstract: A chemical composition which is useful for removing photoresist and polymers from substrates. The composition comprises 10 to 90% by weight of 2-pyrrolidinone compound of the formula C.sub.5 H.sub.9 NO, 10 to 50% by weight of lactic acid of the formula C.sub.3 H.sub.6 O.sub.3, and 10 to 50% by weight of a peroxide compound. The composition of the present invention is particularly useful for cleaning photoresist and removing tough polymers from semiconductor wafer substrates.

Abstract: A composition of matter is set forth which is useful for removing a photoresist material from a substrate. The composition comprises 10 to 90% by weight of a 2-pyrrolidinone compound of the formula ##STR1## 10 to 30% by weight of a diethylene glycol monalkyl ether of the formulaHOCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OR.sub.21 to 10% by weight of a polyglycol having a molecular weight from about 200 to about 600, and 0.5 to 4% of a quaternary ammonium hydroxide of the formulaN.sup.+ R.sub.3 R.sub.4 R.sub.5 R.sub.6 OH.sup.-wherein R.sub.1 is hydrogen, alkyl of 1 to 3 carbon atoms or hydroxyalkyl of 1 to 3 carbon atoms, R.sub.2, R.sub.3 and R.sub.4 are the same or different alkyl groups of 1 to 4 carbon atoms, R.sub.5 is an alkyl group of 1 to 18 carbon atoms, and R.sub.6 is an alkyl group of 1 to 18 carbon atoms, phenyl, alkylphenyl wherein the alkyl is of 1 to 18 carbon atoms, benzyl, or alkylbenzyl wherein the alkyl is of 1 to 18 carbon atoms.