Abstract: A vertical cavity surface emitting laser includes an active area, an inner trench, an outer trench, and a first implantation region. The active area includes a first mirror, an active region, a second mirror, and an etch stop layer. The first mirror is formed over a substrate. The active region is formed over the first mirror. The second mirror is formed over the active region. The etch stop layer with an aperture is formed between the active region and the second mirror. The inner trench surrounds the active area in a top view. The outer trench is formed beside the inner trench. The first implantation region is formed below the inner trench.

Abstract: A vertical cavity surface emitting laser includes an active area, an inner trench, an outer trench, and a first implantation region. The active area includes a first mirror, an active region, a second mirror, and an etch stop layer. The first mirror is formed over a substrate. The active region is formed over the first mirror. The second mirror is formed over the active region. The etch stop layer with an aperture is formed between the active region and the second mirror. The inner trench surrounds the active area in a top view. The outer trench if formed beside the inner trench. The first implantation region is formed below the inner trench.

Abstract: A probe structure is disclosed which includes a metal needle, a soft insulative tube and a metal layer. The metal needle has a first end-portion and a second end-portion opposite to each other. The first end-portion has a tip. The soft insulative tube has a through hole in which the metal needle is partially inserted. The tip of the metal needle protrudes from the through hole. The metal layer is coated on the outer surface of the soft insulative tube and is electrically isolated from the metal needle; the thickness of the metal layer has a thickness no larger than 10 micrometers. Therefore, good resilience and signal integrity could coexist in the probe structure. A probe card including several above-mentioned probe structures and a method for manufacturing the above-mentioned probe structure are also disclosed.

Abstract: A rugged heterojunction bipolar transistor (HBT) power device and the optimal design method thereof are disclosed. By combining the epitaxial layer structure design (embedded emitter ballasting resistor and high breakdown voltage) and power cell design (clamping diodes and base ballasting resistor optimization), HBT power devices with excellent power performance and high ruggedness can be obtained.