Use of contacts to create differential stresses on devices

摘要

Disclosed herein are various methods and structures using contacts to create differential stresses on devices in an integrated circuit (IC) chip. An IC chip is disclosed having a p-type field effect transistor (PFET) and an n-type field effect transistor (NFET). One embodiment of this invention includes creating this differential stress by varying the deposition conditions for forming PFET and NFET contacts, for example, the temperature at which the fill materials are deposited, and the rate at which the fill materials are deposited. In another embodiment, the differential stress is created by filling the contacts with differing materials that will impart differential stress due to differing coefficient of thermal expansions. In another embodiment, the differential stress is created by including a silicide layer within the NFET contacts and/or the PFET contacts.

主权项

1. A method of creating differential stress in a plurality of contacts in an integrated circuit (IC) chip, the method comprising:
providing a substrate including a p-type field effect transistor (PFET) and an n-type field effect transistor (NFET); etching at least one PFET contact trench to the PFET; depositing a first material at a first temperature in the at least one PFET contact trench to form a PFET metal contact within the PFET contact trench; etching at least one NFET contact trench to the NFET; and depositing a second material at a second temperature in the at least one NFET contact trench to form an NFET metal contact within the NFET contact trench, wherein the first temperature of the first material forming the PFET metal contact is higher than the second temperature of the second material forming the NFET metal contact.