It is important to find a way to modulate the work function of TiN metal gate towards the valence band edge of Si,which can meet the lower threshold voltage requirement of p-type metal-oxide-semiconductor（MOS） trans...It is important to find a way to modulate the work function of TiN metal gate towards the valence band edge of Si,which can meet the lower threshold voltage requirement of p-type metal-oxide-semiconductor（MOS） transistor.In this work,effects of TiN thickness,post-deposition annealing（PDA）,oxygen incorporation and N concentration variation on the work function of TiN metal gate in MOS structures are systematically investigated. It can be found that the work function positively shifts at the initial stage as the thickness of the TiN layer increases and stabilizes at such a thickness.PDA at N_2 ambience with a trace of O_2 can also cause a positive shift in the work function of TiN metal gate.The same tendency can be observed when oxygen is incorporated into TiN.Finally, increasing the N concentration in TiN can also positively shift the work function.All these measures are effective in modulating the TiN metal gate so that it is more suitable for PMOS application.展开更多
基金supported by the Important National Science & Technology Specific Projects,China(No.2009ZX02035)the National Natural Science Foundation of China(Nos.61176091,50932001)
文摘It is important to find a way to modulate the work function of TiN metal gate towards the valence band edge of Si,which can meet the lower threshold voltage requirement of p-type metal-oxide-semiconductor（MOS） transistor.In this work,effects of TiN thickness,post-deposition annealing（PDA）,oxygen incorporation and N concentration variation on the work function of TiN metal gate in MOS structures are systematically investigated. It can be found that the work function positively shifts at the initial stage as the thickness of the TiN layer increases and stabilizes at such a thickness.PDA at N_2 ambience with a trace of O_2 can also cause a positive shift in the work function of TiN metal gate.The same tendency can be observed when oxygen is incorporated into TiN.Finally, increasing the N concentration in TiN can also positively shift the work function.All these measures are effective in modulating the TiN metal gate so that it is more suitable for PMOS application.
