Semiconductor device and production method thereof

A production method of a semiconductor device, comprising the steps of:

• forming a lower conductive layer on a surface of or over a semiconductor substrate;
• forming a lower insulating layer on said lower conductive layer;
• forming an intermediate conductive layer on said lower insulating layer;
• forming a first inter-layer insulating layer on said intermediate conductive layer;
• forming a second inter-layer insulating layer on said first inter-layer insulating layer;
• forming a third inter-layer insulating layer on said second inter-layer insulating layer;
• selectively removing said third inter-layer insulating layer thereby forming a first through-hole for wiring extended to said second inter-layer insulating layer, said selective removal action in a direction perpendicular to said third inter-layer insulating layer being stopped by said second inter-layer insulating layer;
• selectively removing said second inter-layer insulating layer, first inter-layer insulating layer and lower insulating layer thereby forming a second through-hole for wiring,
• said second through-hole communicating said first through-hole and extending to said lower conductive layer, an opening area of said second through-hole being smaller in size than an opening area of a top of said first through-hole;
• and
• forming an upper conductive layer for wiring on said third inter-layer insulating layer, which is electrically connected through said first and said second through-holes of said lower insulating layer, first inter-layer insulating layer, second inter-layer insulating layer and third inter-layer insulating layer to the said lower conductive layer, said upper conductive layer not being connected electrically to said intermediate conductive layer;
• wherein said upper conductive layer is in contact with an upper face of said first inter-layer insulating layer in said first contact-hole of said third inter-layer insulating layer.

A semiconductor device comprising:

• a lower conductive layer formed on a surface of or over a semiconductor substrate;
• at least one lower insulating layer formed on said lower conductive layer and having a first through-hole for wiring;
• an intermediate conductive layer formed on said lower insulating layer;
• a first inter-layer insulating layer and a second inter-layer insulating layer formed on said intermediate insulating layer and having a second through-hole for wiring communicated to the first through-hole for wiring of said lower conductive layer and not extended to the first inter-layer insulating layer;
• and
• an upper conductive layer formed on said second inter-layer conductive layer, which is electrically connected through the first and second wiring through-holes of said lower insulating layer and inter-layer insulating layers to said lower conductive layer, said upper conductive layer not being electrically connected to said intermediate conductive layer;
• wherein the thickness of said at least one lower insulating layer adjacent to said first wiring through-hole is formed is thinner than at positions not adjacent to said first wiring through-hole and said lower insulating layer includes a film having a removal action limiting property in the thickness direction when said lower insulating layer is selectively removed to reduce the thickness thereof.

A production method of semiconductor device comprising the steps of:

• forming a lower conductive layer on a surface of or over a semiconductor substrate;
• forming at least one insulating layer on said lower conductive layer;
• selectively removing said at least one lower insulating layer thereby to form a layer area with a small thickness;
• forming an intermediate conductive layer on said at least one lower insulating layer said layer area with a small thickness;
• forming a first inter-layer insulating layer and a second inter-layer insulating layer on said intermediate conductive layer;
• selectively removing said second inter-layer insulating layer thereby to form a first through-hole for wiring, said first through-hole not extending to said first inter-layer insulating layer;
• selectively removing said first inter-layer insulating layer and lower insulating layer to form a second through-hole for wiring which is communicated to the first through-hole of said second inter-layer insulating layer and extended to said lower conductive layer, said second through-hole having an opening area smaller than said first through-hole of said second inter-layer insulating layer;
• and
• forming an upper conductive layer on said second inter-layer insulating layer, which is electrically connected through the first and second wiring through-holes of said lower insulating layer and inter-layer insulating layers, said upper conductive layer extending to said lower conductive layer and not being electrically connected to said intermediate conductive layer;
• wherein the step of selectively removing said lower insulating layer to form a layer area small in thickness utilizes an insulating film which is part of said at least one lower insulating layer and has a function of limiting removal of said lower insulating layer thereby to limit the removal action in the thickness direction thereof.