Methods to form electronic devices and methods to form a material over a semiconductive substrate

A first electrode and a doped oxide layer laterally proximate thereof are provided over a substrate. A silicon nitride layer is formed over both the doped oxide layer and the first electrode to a thickness of no greater than 80 Angstroms over at least the first electrode by low pressure chemical vapor deposition using feed gases comprising a silicon hydride, H2 and ammonia. The substrate with silicon nitride layer is exposed to oxidizing conditions comprising at least 700° C. to form a silicon dioxide layer over the silicon nitride layer, with the thickness of silicon nitride over the doped oxide layer being sufficient to shield oxidizable substrate material beneath the doped oxide layer from oxidizing during the exposing. A second electrode is formed over the silicon dioxide layer and the first electrode. In one implementation, the chemical vapor depositing comprises feed gases of a silicon hydride and ammonia, with the depositing comprising increasing internal reactor temperature from below 500° C. to a maximum deposition temperature above 600° C. and starting feed of the silicon hydride into the reactor at a temperature less than or equal to 600° C. In one implementation the depositing comprises increasing internal reactor temperature from below 500° C. to a maximum deposition temperature above 600° C. using a temperature ramp rate of at least 10° C./minute from at least 500° C. to at least 600° C. Other aspects and implementations are described.