Provided is a method for manufacturing a flash memory device, in which an oxidation process is carried out on the disclosed top surface of a semiconductor substrate to form a surface oxide film in the form of bird’s beak with an appropriate width before conducting an etching process for trench. Diagnostic trees may be modified to include diagnostic code tips or further suggestions or instructions indicating what tool to use or how to use the tool. The target QoS metric may be set to a predetermined value andor may be adjusted dynamically with respect to packet error rate by a slow outer-loop control processor. The secondary i-node contains non-initialized data blocks, and the primary i-node contains valid and initialized data blocks. The device further comprises a micro controller connected to the bus system for providing control signals for each driver unit, such that each LED segment emits light in intensity and color according to a predetermined illumination pattern. The main stent is deployed prior to the branch stent which is then aligned with the side opening of the main stent, and attached at that location.