Patent ID: 8227275

Claim:
A process to form a semiconductor laser diode with a mesa structure, comprising steps of: growing a stack of semiconductor layers on a semiconductor substrate with a surface substantially equal to (001) orientation; iterating a step of dry-etching said stack and a step of ashing, said dry-etching forming said mesa structure with a side surface having a preset angle to said surface of said semiconductor substrate by using an insulating stripe extending along a <110> orientation as an etching mask, said ashing removing residues caused during said step of dry-etching; measuring a growth rate of a semiconductor layer along said <110> orientation and a growth rate of said semiconductor layer along said <001> orientation, wherein said semiconductor layer is made of a same material as a first current blocking layer to be subsequently grown in a next step, and determining a thickness of said first current blocking layer to be thinner than a critical thickness which is derived according to a relation of: x=t mesa /(1+1.43α), wherein x is said critical thickness of said first current blocking layer, t mesa is a height of said mesa structure and α is a ratio of said growth rate along said <110> orientation to said growth rate along said <001> orientation; practically growing said first current blocking layer on both sides of said mesa structure so as to bury said mesa structure; and growing a second current blocking layer on both sides of said mesa structure so as to bury said mesa structure, wherein said first current blocking layer grows along both orientations of <110> on said side surface of said mesa structure and <001> on a surface of said stack exposed by said dry-etching, and wherein said second current blocking layer firstly grows along both orientations of <110> and <001> on said first current blocking layer and secondly grows along both directions of <111> and <001>.