A comparison study of high-density MIM capacitors with ALD HfO/sub 2/-Al/sub 2/O/sub 3/ laminated, sandwiched and stacked dielectrics

The HfO/sub 2/-Al/sub 2/O laminate MIM capacitor exhibits superior performances to the stack and sandwich counterparts, including the smallest linear voltage coefficient of capacitance (/spl beta/) and leakage current, the highest breakdown voltage, the longest time-to-breakdown as well as the most stable quadratic voltage coefficient of capacitance (/spl alpha/) and capacitance under CVS due to weak electron trapping. The underlying mechanism is likely attributed to the alternate insertions of Al/sub 2/O/sub 3/ into the bulk HfO/sub 2/, thereby preventing crystallization of HfO/sub 2/ film.