Transistors, such as metal oxide semiconductor field-effect transistors (MOSFETs), are the core building block of the vast majority of semiconductor devices. Some semiconductor devices, such as high performance processor devices, can include millions of transistors. For such devices, decreasing transistors size, and thus increasing transistor density, has traditionally been a high priority in the semiconductor manufacturing industry. As the size and spacing of the transistors decrease, the dimension constraints for the electrical contacts between the transistors and the interconnecting metal layers also decrease. As a result, it is more difficult to accurately and repeatably form low resistance electrical contacts.
USPTO Backgrounds
USPTO Backgrounds