Device-manufacturing scheme for increasing the density of metal patterns in inter-layer dielectrics

A method comprising:

• forming a transistor comprising:
• forming a gate electrode over a semiconductor substrate;
• and
• forming a source/drain region adjacent the gate electrode;
• forming a guard ring as a heavily doped region in a well region of the semiconductor substrate;
• forming a diode at a surface of the semiconductor substrate;
• forming a first dielectric layer over the guard ring and the diode, wherein the gate electrode comprises at least a portion level with the first dielectric layer;
• forming first metal features, wherein each of the first metal features comprises at least a portion in the first dielectric layer, and wherein the first metal features comprise:
• a first one directly over and electrically coupled to the diode;
• a second one directly over and electrically coupled to the source/drain region;
• and
• a third one directly over and electrically coupled to the guard ring;
• forming a second dielectric layer over the first dielectric layer;
• forming second metal features in the second dielectric layer, wherein the second metal features comprise a first one, a second one, and a third one directly over and electrically connected to the first, the second, and the third ones of the first metal features, respectively;
• removing at least one of the first and the third ones of the second metal features to form at least a first opening, wherein a respective one of the first metal features is exposed through the first opening;
• patterning the second dielectric layer to form a second opening, wherein a portion of the gate electrode is exposed through the second opening;
• and
• filling the first and the second openings with a metallic material to form third metal features.

A method comprising:

• forming first metal features comprising at least portions at a same level as a gate electrode of a transistor formed at a top surface of a semiconductor substrate;
• forming a second metal feature over and contacting the first metal feature;
• forming a third and a fourth metal feature in the same process step, wherein the third metal feature is over and contacting the first metal feature, and wherein the fourth metal feature is directly over and contacting the gate electrode;
• forming metal vias over and contacting the third and the fourth metal features;
• and
• forming metal lines over and contacting the metal vias.