Spacer formation for array double patterning

A method for forming an array area with a surrounding periphery area, wherein a substrate is disposed under an etch layer, which is disposed under a patterned organic mask defining the array area and covers the entire periphery area is provided. The patterned organic mask is trimmed. An inorganic layer is deposited over the patterned organic mask where a thickness of the inorganic layer over the covered periphery area of the organic mask is greater than a thickness of the inorganic layer over the array area of the organic mask. The inorganic layer is etched back to expose the organic mask and form inorganic spacers in the array area, while leaving the organic mask in the periphery area unexposed. The organic mask exposed in the array area is stripped, while leaving the inorganic spacers in place and protecting the organic mask in the periphery area.