초록 |
The device coupling between the stacked top/bottom field-effect transistors (FETs) in two types of monolithic 3D inverter (M3INV) with/without a metal layer in the bottom tier is investigated, and then the regime of the thickness T ILD and dielectric constant epsilon; r of the inter-layer distance (ILD), the doping concentration N d (N a ), and length L g of the channel, and the side-wall length L SW where the stacked FETs are coupled are studied. When N d (N a ) 16 cm -3 and L SW d (N a ) gt; 10 16 cm -3 or L SW gt; 20 nm, the shift decreases and increases, respectively. M3INVs with T ILD ge; 50 nm and epsilon; r le; 3.9 can neglect the interaction between the stacked FETs, but when T ILD or epsilon; r do not meet the above conditions, the interaction must be taken into consideration. |