Method for fabrication of monolithic integrated circuits

A method for producing a monolithic integrated circuit comprising the steps of:

• A. isolating for the site of an active device an area of a substrate having a doped layer of N material covered by a highly doped layer of N material;
• B. depositing a first layer of Ta thereover;
• C. depositing a layer of Au thereover;
• D. depositing a second layer of Ta thereover;
• E. photolithographically removing portions of said second Ta layer and leaving configured other portions of it at least at said selected active device area;
• F. enclosing the substrate in an environmentally isolated chamber;
• G. depositing another layer of Au over (a) the remaining portions of said second Ta layer and (b) said first Au layer at said other portions wherein said second Ta layer was removed, to bury said configured Ta layer within the gold;
• H. providing over a substantial portion of a surface of the substrate at least five more superimposed layers of metals and compounds, wherein said metals include at least one from the group tantalum, molybdenum, tungsten, and gold, and wherein said compounds include at least one from the group of oxides of tantalum, molybdenum, and tungsten, and silicon nitride;
• I. removing the circuit from said chamber;
• J. sequentially processing patterned areas of said layers substantially from the exposed top layer downward, to define circuit elements forming a substantially complete integrated circuit including the active device, by processes including photolithography;
• K. wherein said step J comprises removing said portions of the layer of Au that overlie said buried Ta layer item (a) of step G, and leaving in place said layer of Au that was at said other portions, item (b) of step G.

A method for producing a monolithic integrated circuit comprising the steps of:

• A. providing a doped layer followed by a highly doped layer on a substrate on a selected area intended for an active device;
• B. enclosing the substrate in an environmentally isolated chamber;
• C. providing over a substantial portion of a surface of the substrate at least seven superimposed layers of metals, oxides and nitrides, wherein said metals include at least one from the group tantalum, molybdenum, tungsten, and gold, and wherein said oxides include at least one from the group of oxides of tantalum, molybdenum, and tungsten, wherein all of said at least seven superimposed layers are formed in situ in the same said chamber without removal from said chamber;
• D. removing the circuit from said chamber;
• and
• E. sequentially processing patterned areas of said layers substantially from the exposed top layer downward, to define circuit elements forming a substantially complete integrated circuit including the active device, by processes including photolithography.

A method for producing a monolithic integrated circuit comprising the steps of:

• A. providing a doped layer of N material followed by a highly doped layer of N material on at least an area of a substrate selected for locating an active device;
• B. depositing a first layer of Ta thereover;
• C. depositing a layer of Au thereover;
• D. depositing a second layer of Ta thereover;
• E. photolithographically removing portions of said second Ta layer and leaving configured other portions of it at least at said selected active device area;
• F. enclosing the substrate in an environmentally isolated chamber;
• G. depositing another layer of Au over (a) the remaining portions of said second Ta layer and (b) said first Au layer at said other portions where said second Ta layer was removed, to bury said configured Ta layer within the gold;
• H. providing over a substantial portion of a surface of the substrate at least seven superimposed layers of metals and compounds, wherein said metals include at least one from the group tantalum, molybdenum, tungsten, and gold, and wherein said compounds include at least one from the group of oxides of tantalum, molybdenum, tungsten, and silicon nitride;
• I. removing the circuit from said chamber;
• and
• J. sequentially processing patterned areas of said layers substantially from the exposed top layer downward, to define circuit elements forming a substantially complete integrated circuit including the active device, by processes including photolithography;
• K. wherein said step J comprises selectively removing said portions of the layer of Au that overlie said buried Ta layer item (a) of step G, and leaving said layer of Au that was at said other portions, item (b) of step G.