Low dielectric constant insulating film and preparation method thereof

The invention belongs to the technical filed of integrated circuit materials, in particular to a low dielectric constant insulating film and a preparation method thereof. The low dielectric constant insulating film is a SiCONF film and comprises main components of silicon (Si), carbon (C), oxygen (O), nitrogen (N) and fluorine (F), and the thickness of the film is 20-500 nm. The low dielectric constant insulating medium SiCONF film can be prepared by a plasma enhanced chemical vapor deposition (PECVD) method; a plasma generation device added in PECVD equipment can be used as a device adopted by the method; and plasma is generated by the PECVD equipment and the radio-frequency range of the prior plasma radio-frequency excitation source can be used. The SiCONF film has low dielectric constant and leak current density, high thermal stability and favorable mechanical property and can be compatible with the prior integrated circuit process.