how metal 1 layer is isolated from the poly silicon layer

做cmos inverter layout时。有一问是这样 Draw a cross section of your design and explain how metal 1 layer is isolated from the poly silicon layer.
望前辈们指点

help,自救一下

问你metal1如何和poly隔开，两个中间有fox吧，通过contact连接

metal1和poly通过contact连接，metal1和poly通过oxide进行隔离。