Simultaneous location of areas having different conductivities

The process of introducing impurities into a substrate of material in the manufacture of a semiconductor device comprising the steps of:

• a. forming a first layer of a first material over said substrate;
• b. forming a second layer of a second material over said first layer, said second material being different from said first material;
• c. preferentially etching portions of said second layer by an etchant which preferentially etches said second material with respect to said first material to expose the underlying portions of said first layer;
• d. removing said exposed portions of said first layer to expose the underlying portions of said substrate;
• e. forming a third layer of said second material over said exposed portions of said substrate;
• f. simultaneously defining selected portions of said second and said third layers, then removing said selected portions of said third layer to expose the underlying portions of said substrate while simultaneously removing said selected portions of said second layer to expose the underlying portions of said first layer, the removal of said selected portions being accomplished by an etchant which preferentially etches said second material with respect to said first material;
• g. depositing impurities of a first conductivity type onto the exposed portions of said substrate and introducing said impurities into said substrate;
• h. forming fourth layers of said second material only over the exposed portions of said substrate by reacting said exposed portions of said substrate;
• i. removing the remaining said exposed portions of said first layer to expose the underlying portions of said substrate;
• and
• j. depositing impurities of a second conductivity type different from said first conductivity type into said exposed portions of said substrate and introducing said impurities into said substrate.