I ask for a tool by which I could design an analog/mixed-signal circuit containing OTFT, this tool should have all the steps in IC design (LVS, PEX, ..)
Any IC design tool should be able to support this kind of design. What you need is a design kit - the set of files that describes the process to the tools and allows you to design circuits. As an example, the open-source design tool Electric VLSI includes a "tft" technology: http://www.staticfreesoft.com/jmanual/mchap07-01-01.html