The present invention provides a method for forming a semiconductor region having a desired shape, and also provides a method for manufacturing a semiconductor device with few variations. More particularly, provided are an activation method of a newly prepared catalyst and a regeneration method of a deactivated metal oxide catalyst. Then, a data structure of the input data is transformed into a bitmapping data structure. The trash compactor can include a storage system to store power for compaction cycles. Microelectronic devices may be formed in the overgrown gallium nitride semiconductor layer.