Abstract: A negative feedback avalanche diode for detecting the receipt of a single photon is described. The photodetector comprises a load element having two load states, one characterized by high impedance and the other characterized by low impedance. The load state of the load element is controlled by a control signal generated within the negative feedback avalanche diode itself.

Abstract: Methods for forming a buried p-n junction and avalanche photodiodes incorporating same are disclosed. The method includes forming a well in a semiconductor layer, wherein a depth of the well is selected as a function of the desired shape of the p-n junction in the edge region of the avalanche photodiode. A diffusion mask is then formed on the semiconductor layer, wherein the diffusion mask includes at least two openings per APD formed, wherein one opening is a diffusion window and the other is a diffusion sink. The depth of the p-n junction in the active region of the APD is based, in part, on an attribute of the diffusion mask relating to the diffusion sink.

Abstract: A method for aligning a first substrate relative to a second substrate by enabling reflow of low-melting-temperature solder bumps is disclosed. Reflow of the solder bumps induces a force that moves one substrate relative to the other to improve alignment accuracy between bond pads located on each substrate. The method further enables reduction of surface oxide on the solder bumps that would otherwise inhibit reliable solder joint formation.