Abstract A semiconductor device has a funnel shaped contact window (30) for providing an inter-level connection between a lower silicon or polysilicon film (22) and an upper metal wiring strip (32), and the funnel shaped contact window is formed in an inter-level insulating film structure (27) consisting of a lower insulating film (28) of phosphosilicate glass and an upper insulating film (29) of silicon dioxide, since an isotropical etching is firstly applied to the silicon dioxide film and followed by an anisotropical etching to the phosphosilicate glass film by using the same mask layer, the lower portion of the contact window is smaller in cross sectional area than the upper portion, and the funnel shaped contact window thus formed is effective to create a smooth topography of an upper metal wiring strip for preventing from undesirable disconnection.
A semiconductor device having at least one transistor, comprising a) a lower conductive layer, b) an inter-level insulating film structure provided on said lower conductive layer, a contact window being formed in said inter-level insulating film structure, c) an inter-level connection provided in said contact window and contacting at the bottom surface thereof with said lower conductive layer, and d) an upper conductive layer formed on said inter-level insulating film structure and electrically connected to said inter-level connection, characterized in that said inter-level insulating film structure comprises a lower insulating film having a lower part of said contact window and an upper insulating film having an upper part of said contact window, and in that the lower part of said contact window is smaller in cross sectional area than the upper part of the contact window.
Claim 2
Dependent Claim
136 words
A semiconductor device having at least one transistor, comprising a) a lower conductive layer, b) an inter-level insulating film structure provided on said lower conductive layer, a contact window being formed in said inter-level insulating film structure, c) an inter-level connection provided in said contact window and contacting at the bottom surface thereof with said lower conductive layer, and d) an upper conductive layer formed on said inter-level insulating film structure and electrically connected to said inter-level connection, characterized in that said inter-level insulating film structure comprises a lower insulating film having a lower part of said contact window and an upper insulating film having an upper part of said contact window, and in that the lower part of said contact window is smaller in cross sectional area than the upper part of the contact window.
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