Integrated circuit contact technique

Technique for simultaneously forming separate windows to impurity regions of both n- and p-type in a semiconductor substrate comprising the steps of:

• forming a region of a first impurity type in a portion of the substrate having the opposite conductivity type
• forming an insulating layer over at least a portion of the substrate said portion including said region,
• forming a window in said insulating layer exposing a portion of said region and a first portion of the substrate having the opposite impurity type,
• forming a window in said insulating layer exposing a second portion of the substrate having the opposite impurity type, said second portion having an impurity level of said opposite impurity type higher than the impurity level of the first portion,
• implanting into both windows simultaneously impurities of said first type to a level sufficient to convert said first portion of the substrate to the first impurity type but insufficient to convert the second portion of the first conductivity type.

Technique for forming contacts to complementary impurity regions in a CMOS device comprising the steps of:

• forming a first region having a first impurity type in a substrate portion of the opposite impurity type,
• forming a second region having the opposite impurity type in a substrate portion of the first impurity type, said second region having an imprity level substantially higher than the impurity level of said substrate portion of the opposite type and second region being substantially larger than said first region,
• forming an insulating layer over said regions,
• forming a first window in said insulating layer said window exposing a portion of said first region and a portion of said substrate portion of the opposite impurity type,
• forming a second window in said insulating layer said second window exposing a portion of said second region,
• implanting impurities of said first type into both windows simultaneously at a level sufficient to convert said portion of the substrate of the opposite impurity type to said first impurity type, but insufficient to convert said second region to said first conductivity type,
• and forming electrical contacts to said first and second regions by depositing conductive material over said substrate and into said windows.

Method comprising:

• forming a first region of a first conductivity type in a semiconductor substrate,
• forming a second region of a first conductivity type in the substrate said second region having an impurity level of said first conductivity type substantially higher than the level in the said first region,
• forming a region of the opposite conductivity type in the substrate,
• implanting into all three regions simultaneously impurities of the opposite conductivity type at a dose sufficient to convert said first region to the opposite conductivity type but insufficient to convert the second region to the opposite conductivity type.