Abstract:
A optimized process consisting of two-step selective etching is proposed to solve the problem that the selectivity between TiN/Ti and TiSi
2 is poor with the conventional RCA1(NH
4OH:H
2O
2:H
2O) solution and results in a loss of a substantial part of the formed silicide thickness and hence in an increase of the contact resistance.Compared to the traditional process, this process allows an important reduction of the TiSi
2 thickness loss and hence, makes the reduction of the sheet resistance about 18%.Furthermore, this process is feasible and controllable, which makes it adapt to manufacture in industry.