A comparative study of self-aligned quadruple and sextuple patterning techniques for sub-15nm IC scaling

Cut-hole layout decomposition and synthesis to reduce the effect of edge-placement errors

“…On the other hand, the final space between any two adjacent lines is fixed at the width of spacer 2. [4][5][6], there are also three consecutive spacer steps in an altSASP process that enable spatial frequency sextupling. However, an altSASP process differs from a SASP process in that spacer 1 (material A) and spacer 3 (material B) are made of different materials, as shown in Fig.…”

“…Therefore each separate cut-hole patterning process can tolerate more edge-placement errors. [4][5][6], the mandrel patterns in an altSAQP process are generated first and spacer 1 is formed on the mandrel sidewalls ( Fig. 2(a)).…”

“…The patterning process starts from a line/trench fabrication step followed by a line-cut/trench-block step to form the desired high-density IC patterns [3]. For instance, the first (line-fabrication) step can be accomplished by a variety of lithography techniques including EUV, self-aligned multiple patterning (SAMP [4][5][6]), optical multiple patterning, and directed self-assembly (DSA). In particular, the self-aligned multiple patterning and directed self-assembly both have the potential to pattern sub-10 nm (half-pitch) lines with excellent CD uniformity [6][7].…”

Benchmarking process integration and layout decomposition of directed self-assembly and self-aligned multiple patterning techniques

“…DSA is a cost-effective frequency multiplication process using pre-patterned templates, which is similar to self-aligned multiple patterning (SAMP [18][19][20][21][22][23][24][25][26][27][28][29][30][31]) based on mandrel and spacer engineering. SAMP technique is a proven solution to pattern 1-D structures of both memory and logic devices.…”

“…SAMP layout decomposition [24][25][26][27][28][29][30][31] needs to deal with the complicated interaction between mandrels and spacers, and possibly extra mask(s) to introduce more 2-D design freedom. Consequently, SAMP layout decomposition is not as intuitive as optical multiple patterning.…”