Work function adjustment in high-k metal gate electrode structures by selectively removing a barrier layer

• Main Authors: LENSKI MARKUS, BINDER ROBERT, METZGER JOACHIM, HEMPEL KLAUS, SCHROEDER VIVIEN
• Format: Patent
• Language: English
• Published: 30.10.2012
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

In a replacement gate approach in sophisticated semiconductor devices, a tantalum nitride etch stop material may be efficiently removed on the basis of a wet chemical etch recipe using ammonium hydroxide. Consequently, a further work function adjusting material may be formed with superior uniformity, while the efficiency of the subsequent adjusting of the work function may also be increased. Thus, superior uniformity, i.e., less pronounced transistor variability, may be accomplished on the basis of a replacement gate approach in which the work function of the gate electrodes of P-channel transistors and N-channel transistors is adjusted after completing the basic transistor configuration.