Semiconductor devices and structures, such as phase change memory devices, include peripheral conductive pads coupled to peripheral conductive contacts in a peripheral region. An array region may include memory cells coupled to conductive lines. Methods of forming such semiconductor devices and structures include removing memory cell material from a peripheral region and, thereafter, selectively removing portions of the memory cell material from the array region to define individual memory cells in the array region. Additional methods include planarizing the structure using peripheral conductive pads and/or spacer material over the peripheral conductive pads as a planarization stop material. Yet further methods include partially defining memory cells in the array region, thereafter forming peripheral conductive contacts, and thereafter fully defining the memory cells.