公开(公告)号：JPH11340586A

公开(公告)日：1999-12-10

申请号：JP12334099

申请日：1999-04-30

Applicant: LUCENT TECHNOLOGIES INC

Inventor： CAPASSO FEDERICO ,  CHO ALFRED Y ,  FAIST JEROME ,  GMACHL CLAIRE F ,  HUTCHINSON ALBERT LEE ,  SIVCO DEBORAH LEE ,  TREDICUCCI ALESSANDRO

IPC: H01S5/00 ,  H01S5/042 ,  H01S5/30 ,  H01S5/34 ,  H01S5/343 ,  H01S3/18

Abstract: PROBLEM TO BE SOLVED: To use a unit which is effective for monitoring contamination by collecting multiple identical repetitive units so as to form a waveguide core area, and constituting the repetitive units of injector areas and superlattice active regions. SOLUTION: A waveguide core region 13 is formed between a substrate/ lower-order optical close region 12 and a higher-order optical close region 14. The waveguide core area 13 is constituted by gathering multiple identical repetitive units. The repetitive units are constituted of injector regions which are injection/relief areas and superlattice active regions selected so that radiative carriers from a higher-order energy level to a lower-order energy level in the superlattice active region can easily be shifted. Thus, the diffusion of the carriers becomes less, an optical loss can be reduced, and the unit can used effectively be for monitoring of contamination.

公开(公告)号：JPH10242465A

公开(公告)日：1998-09-11

申请号：JP4168598

申请日：1998-02-24

Applicant: LUCENT TECHNOLOGIES INC

Inventor： CHO ALFRED Y ,  HONG MINGHWEI ,  JAMES ROBERT ROSHIAN ,  MANNAERTS JOSEPH P ,  REN FAN

IPC: H01L29/78 ,  B82B1/00 ,  H01L21/28 ,  H01L21/336 ,  H01L21/8234 ,  H01L27/088 ,  H01L29/51

Abstract: PROBLEM TO BE SOLVED: To form the alloy of an ohmic metal contact by allowing a gate oxide layer of a product including a metal/oxide/semiconductor field effect transistor on the basis of a first GaAs where a gate metal contact is arranged on a gate oxide layer as a base to be Gd-Ga oxide with a specific Gd:Ga atom ratio. SOLUTION: A protection dielectric layer is formed by depositing SiO2 . The formation of an alloy of an ohmic metal is performed at a temperature within a range of, for example, 400±50 deg.C in He atmosphere in a typical case. The elimination of the protection dielectric requires strictness for preventing the gate oxide from being damaged. More specifically, the composition of the gate oxide is selected properly, namely a Gd-Ga oxide with a Gd-Ga ratio that is 1:7.5 or preferably 1:4 or 1:2 or larger. The etching speed of Gd-Ga oxide in an HF solution depends on the Gd content of the oxide. Therefore, the protection dielectric on the gate oxide can be eliminated without losing the gate oxide and the alloy of the ohmic metal contact can be formed.