Method of manufacturing an insulating layer and method of manufacturing a semiconductor device using the insulating layer

A method of manufacturing a semiconductor device, the method comprising:

• forming a conductive pattern on a first insulating layer, the conductive pattern having an opening partially exposing the first insulating layer;
• forming a preliminary second insulating layer on the first insulating layer and the conductive pattern, the preliminary second insulating layer filling up the opening, the preliminary second insulating layer including a material having a relatively low dielectric constant;
• providing an upper portion of the preliminary second insulating layer with an ozone gas under a dry atmosphere to transform the preliminary second insulating layer into a second insulating layer comprising an upper insulating film including an oxide and a lower insulating film including the material having the relatively low dielectric constant, the upper insulating film covering an upper face of the conductive pattern, the lower insulating film formed under the upper insulating film;
• forming a third insulating layer on the upper insulating film;
• forming a conductive plug through the third insulating layer and the upper insulating film to be electrically connected to the conductive pattern;
• and
• forming a conductive layer on the conductive plug and the third insulating layer,
• wherein the forming of the preliminary second insulating layer includes coating the object with a fluid including the material having the relatively low dielectric constant and a solvent, and performing a thermal treatment on the fluid at a temperature of about 70° C. to about 370° C.

A method of forming an insulating layer, the method comprising:

• forming a preliminary spin-on layer on an object, the preliminary spin-on layer including a material having a relatively low dielectric constant and a porogen;
• performing a first thermal treatment on the preliminary spin-on layer to form a spin-on layer including a plurality of pores;
• performing an ozone treatment on the spin-on layer to form a preliminary insulating layer comprising a preliminary upper insulating film including an oxide and a preliminary lower insulating film including the material having the relatively low dielectric constant, wherein the pores in the preliminary upper insulating film are removed;
• and
• performing a second thermal treatment on the preliminary insulating layer to form an insulating layer comprising an upper insulting film and a lower insulating film, wherein the second thermal treatment removes byproducts and moisture from the upper preliminary insulating layer.