Abstract: A method for forming a high electron mobility transistor is disclosed. A mesa structure having a channel layer and a barrier layer is formed on a substrate. The mesa structure has two first edges extending along a first direction and two second edges extending along a second direction. A passivation layer is formed on the substrate and the mesa structure. A first opening and a plurality of second openings connected to a bottom surface of the first opening are formed and through the passivation layer, the barrier layer and a portion of the channel layer. In a top view, the first opening exposes the two first edges of the mesa structure without exposing the two second edges of the mesa structure. A metal layer is formed in the first opening and the second openings thereby forming a contact structure.

Abstract: An apparatus and a method of controlling clock signals for a master device and a slave device are disclosed. The controlling apparatus includes: a first connection port coupled to a first clock line of the master device; a second connection port coupled to a second clock line of the slave device; and a control module receiving a first clock signal from the master device via the first connection port, producing a second clock signal according to the first clock signal, and transmitting the second clock signal to the slave device via the second connection port; wherein when the first clock signal is switched from a first logic level to a second logic level, the control module controls the first connection port to maintain the second logic level in a time interval.

Abstract: An apparatus and a method of controlling clock signals for a master device and a slave device are disclosed. The controlling apparatus includes: a first connection port coupled to a first clock line of the master device; a second connection port coupled to a second clock line of the slave device; and a control module receiving a first clock signal from the master device via the first connection port, producing a second clock signal according to the first clock signal, and transmitting the second clock signal to the slave device via the second connection port; wherein when the first clock signal is switched from a first logic level to a second logic level, the control module controls the first connection port to maintain the second logic level in a time interval.