Two-color self-aligned double patterning (sadp) to yield static random access memory (sram) and dense logic

A method of forming a semiconductor region, the method comprising:

• providing a first set of features corresponding to a first lithography process, each feature of the first set of features having a first width;
• subsequent to providing the first set of features, forming a second set of features corresponding to a second lithography process;
• forming a first set of mandrels corresponding to the first set of features and a second set of mandrels corresponding to the second set of features, wherein a first mandrel of the first set of mandrels is adjacent to a first mandrel of the second set of mandrels;
• concurrently forming spacers on the first and second sets of mandrels, wherein the mandrels of the first set of mandrels have substantially the first width when the spacers are formed;
• removing the first and second sets of mandrels to form an intermediate fin pattern, the intermediate fin pattern comprising:
• first and second intermediate fins corresponding to spacers on opposite sides of the first mandrel of the first set of mandrels;
• and
• third and fourth intermediate fins corresponding to spacers on opposite sides of the first mandrel of the second set of mandrels, wherein the second and third intermediate fins are adjacent intermediate fins;
• and
• performing an etch to transfer the intermediate fin pattern to a substrate to form first, second, third, and fourth semiconductor fins.