Semiconductor device

Abstract

Abstract PURPOSE:To prevent an opening area from being reduced and to reduce a contact resistance by a method wherein a sidewall of a silicon nitride film is formed on an inner face of a contact hole which has been made in an insulating film formed by a reflow operation. CONSTITUTION:An oxide film 2 and a borophosphosilicate glass(BPSG) film 3 are formed one after another on a silicon substrate 1; the BPSG film 3 and the oxide film 2 are etched one after another to open a contact hole. After that, a nitride film is formed on the whole surface; it is etched back to form a nitride-film side wall 4 on an inner face of the contact hole, i.e. on a side face of the BPSG film 3 and the oxide film 2. Then, impurities are introduced into the silicon substrate 1 through the contact hole; they are annealed and activated to reduce a contact resistance. During this process, the BPSG film 3 is not melted and its shape is not collapsed. Thereby, it is possible to prevent an opening area of the contact hole from being reduced and to prevent the contact resistance from being increased.

Inventors

• 👤 Koji Kanba
• 👤 康二 神庭

Bibliographic Details