Electrical Properties of Silicon Dioxide Films Fabricated at 700°C: III . High Pressure Thermal Oxidation

Abstract

High quality thermal oxides of silicon have been fabricated on silicon substrates over the oxidation temperature range 635~176 Dry, high pressure oxidation (DRYPOX) was used to grow oxides at temperatures below 1000~ The high pressure range investigated was 2-500 arm. Standard capacitance-voltage techniques have been used to characterize these oxides in terms of oxide fixed change (Q~) and interface trap densities (Di,). Additionally, avalanche injection of both electrons and holes has been used to evaluate the charge trapping properties of these films. The electron trapping properties of 685~ high pressure oxides were compared with "conventional" 1000~ oxides fabricated at 1 arm and with oxides fabricated using low pressure chemical vapor deposition (LPCVD) at 730~ The results of these experiments were as fellows: (i) basic electrical properties of high pressure oxides, as well as hole and electron trapping behavior in these oxides, were similar to those of 1000~ conventional oxides; (it) hole trap densities exhibited a broad minimum at an oxidation temperature between 800 ~ and 900~ and (iii) electron trapping behavior in 685~ DRYPOX oxides was markedly superior to that in 730~ LPCVD oxides. The LPCVD oxide required an anneal at 1000~ to produce electron trapping characteristics comparable to those of DRYPOX samples processed entirely at temperatures below 700~