A process applicable to the production of monocrystalline films improves on the Smart-Cut.RTM. process by using an etch stop layer in conjunction with the Smart-Cut.RTM. process. Because of the etch stop layer, no chemical-mechanical polishing (CMP) is required after fabrication. Thus, the thickness and smoothness of the device layer in the fabricated silicon on insulator (SOI) substrate is determined by the uniformity and smoothness of the deposited layers and wet etch selectivity, as opposed to the CMP parameters. Therefore, the smoothness and uniformity of the device layer are improved.