Levelling method of insulation layer

Abstract

Abstract PURPOSE:To decrease unevenness of the surface and permit buried construction of an insulation layer by arranging two layers of insulation films, a film of Si nitride as a principal component for the upper layer, on the uneven surface of the substrate. CONSTITUTION:A thermally oxidized film 2 is formed on a substrate 1, and for example, Al wiring of 1mum thickness is applied on the film 2, and an SiO2 film 41 and an Si nitride film 42 of each thickness of 1mum are attached at low temperature. Then the raised part of the film 41 is etched by 0.5mum by the process of reactive ion etching using a gas mixture of H2 (27%) and CF4. In this etching method, the surface can be leveled because the raised part of the film 42 is etched faster than the recessed part, and etching speed is the same for the films 41 and 42. Also by etching treatment with two layers, the films 41 and 42, arranged as above on the substrate 1 with ditches at the separating region, a constitution of SiO2 film 41 buried in the ditch can be formed evenly without widening or forming birdbeaks.

Inventors

• 👤 Riyouichi Hazuki
• 👤 Takahiko Moriya
• 👤 Masahiro Kashiwagi

Bibliographic Details