Insulating layer, semiconductor device and methods for fabricating the same

A method for forming an insulating layer comprising:

• preparing an oxidizing atmosphere by supplying oxygen gas into a chamber to surround a substrate on which the insulating layer will be formed;
• forming a first seed layer of said insulating layer on said substrate by supplying a tetraethylorthosilicate (TEOS) and the oxygen gas into the chamber;
• forming a second seed layer of said insulating layer, said second seed layer capable of controlling an amount of boron added to said first seed layer by supplying triethylborate (TEB), the TEOS and the oxygen gas into the chamber;
• and
• forming a BPSG layer as the insulating layer, which includes said first seed layer and said second seed layer, said BPSG layer capable of controlling the amount of the boron and phosphorus added thereto by supplying the TEB, the TEOS, triethylphosphate (TEPO), and an ozone gas into the chamber.

A method for fabricating a semiconductor device comprising:

• forming an etch stop layer on a substrate for preventing said substrate from being damaged by etching;
• forming an insulating layer, to which about 5.25-5.75% by weight of boron and about 2.75-4.25% by weight of phosphorus is added, on said etch stop layer;
• reflowing said insulating layer to evenly form an upper surface of said insulating layer, and simultaneously charging recessed regions with said insulating layer among elevated regions and recessed regions of said substrate;
• and
• etching a predetermined portion of said insulating layer to form an insulating layer pattern having a window which exposes an upper surface of said underlying etch stop layer.