Process for fabricating an avalanche photodiode
AssigneeFujitsu Limited
InventorsKazuhito Yasuda, Yutaka Kishi
Life of this patent
Estimating the term…
Abstract
Disclosed is an avalanche photodiode wherein a light absorption layer and a multiplication layer are first grown on substrate. The multiplication layer is then mesa-etched and another semiconductor layer is second grown on the mesa-etched multiplication layer. A dopant having a conductivity opposite to that of the above layers is introduced from the top of the another semiconductor layer to form a doped region extending inside the mesa portion and p-n junction is therefore formed inside the mesa-etched portion. This causes the distribution of multiplication in the active area to become uniform, since the rough surface of the top of the mesa-etched portion exists outside the multiplication region.
Claims6
A process for fabricating an avalanche photodiode, comprising the steps of:
- carrying out a first crystal growth for forming a first semiconductor layer of a first conductivity type on a semiconductor body comprising a light absorption layer;
- selectively etching a periphery of said first semiconductor layer to leave the first semiconductor layer in the form of a mesa;
- melting-back the exposed surface of the first semiconductor layer in the form of a mesa;
- carrying out a second crystal growth for forming a second semiconductor layer on said mesa-etched and melted-back first semiconductor layer;
- and
- forming an impurity doped region of a second conductivity type extending from the top surface of said second semiconductor layer into the inside of said first semiconductor layer, whereby a p-n junction is defined in said inside of said first semiconductor layer and the remaining portion of said first semiconductor layer where said impurity doped region is not formed defines a multiplication layer.
Dependencies are inferred from the claim text.