摘要:
Disclosed are a robot cleaner and a method for controlling the same. Firstly, an obstacle may be detected by using a light pattern sensor, and a user's inconvenience due to irradiation of a light pattern may be solved. Secondly, an obstacle may be precisely detected in a three dimensional manner by using the light pattern sensor. This may allow precise creation of a cleaning map. Thirdly, a user's eyes may be prevented from being continuously exposed to a light source. This may enhance the user's convenience.
摘要:
According to example embodiments of inventive concepts, a method of fabricating a 3D semiconductor device may include: forming a stack structure including a plurality of horizontal layers sequentially stacked on a substrate including a cell array region and a contact region; forming a first mask pattern covering the cell array region and defining openings extending in one direction over the contact region; performing a first etching process with a first etch-depth using the first mask pattern as an etch mask on the stack structure; forming a second mask pattern covering the cell array region and exposing a part of the contact region; and performing a second etching process with a second etch-depth using the second mask pattern as an etch mask structure on the stack structure. The second etch-depth may be greater than the first etch-depth.