Method for fabricating an n-type semiconductor material using silane as a precursor

A method for fabricating a group III-V n-type nitride structure, the method comprising:

• fabricating a growth Si substrate;
• depositing a group III-V n-type layer above the Si substrate using silane gas (SiH4) as a precursor at a flow rate set to a first predetermined value corresponding to a first carrier density;
• reducing the SiH4 flow rate to a second predetermined value corresponding to a second carrier density during the fabrication of the n-type layer, wherein the second carrier density is less than the first carrier density;
• and
• forming a multi-quantum-well active region above the n-type layer;
• wherein the flow rate is reduced over a predetermined period of time;
• and
• wherein the second predetermined value is reached at a predetermined, sufficiently small distance from the interface between the n-type layer and the active region.