Stress reduction in AlGaAs-AlGaAsP multilayer structures
AssigneeBell Telephone Laboratories, Incorporated
InventorsMorton B. Panish, George Arthur Rozgonyi
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Abstract
The average stress between contiguous layers of Al.sub.x Ga.sub.1.sub.-x As and Al.sub.y Ga.sub.1.sub.-y As (y > x) is reduced by the addition of phosphorus during the growth of the latter layer to produce the quaternary Al.sub.y Ga.sub.1.sub.-y As.sub.1.sub.-z P.sub.z instead of the ternary Al.sub.y Ga.sub.1.sub.-y As. In order to reduce the average stress to less than about 2 .times. 10.sup.8 dynes/cm.sup.2 the amount of phosphorus added should satisfy the condition: ##EQU1## Also described is a double heterostructure junction laser comprising a GaAs or AlGaAs active layer sandwiched between layers of AlGaAsP.
Claims10
A multilayer structure comprising
- a first layer of Al.sub.x Ga.sub.1.sub.-x As,
- a second layer of Al.sub.y Ga.sub. 1.sub.-y As.sub.1.sub.-z P.sub.z contiguous with said first layer,
- the fraction y of Al is said second layer exceeding the fraction x of Al in said first layer, and
- the fractions of Al, Ga and P in said first and second layers being mutually adapted to reduce the average stress in said second layer as compared with the stress which would be produced in the absence of phosphorus therein at substantially room temperature.
Dependencies are inferred from the claim text.