Method for manufacturing an optical module and optical module

DETAILED DESCRIPTION The present invention provides for an improved method for manufacturing an optical module as claimed in the independent claims.
Preferred embodiments of the invention are set forth in the dependent claims.
It is a particular advantage of the present invention that the deposition of an aluminium layer from the front side of the substrate can be avoided.
Rather the aluminium layer is either deposited from the backside of the substrate through a hole formed in the backside by the positioning groove or the aluminium layer is formed on a portion of the optical component itself prior to positioning the optical component within the groove.
In accordance with a preferred embodiment of the invention the substrate, i.
e.
the wafer, is etched in an anisotropic way to form a deep V-groove for providing an opening at the backside of the substrate.
This etching step enables to accurately align the optical component to be bonded whereas the opening is used as a backside access for deposition of the aluminium layer.
In accordance with a further preferred embodiment of the invention the attachment of the optical component to the substrate is achieved by using aluminium deposition (like vapour deposition or sputtering) such that an aluminium layer is formed on the substrate backside and extending through the opening onto the lower portion of the optical component.
This way the contact area of the aluminium layer and the optical component is much larger in comparison to the prior art where only point contacts are formed.
In accordance with a further preferred embodiment of the invention the aluminium layer is formed on the backside of the substrate during one of the final processing steps of the manufacturing of the optical module, such as during the assembly part of the manufacturing process.
This is made possible by the present invention as the aluminium layer is not part of the submount structurization itself.
This has the further advantage that the aluminium surface is not subjected to any of the aggressive processing steps which are required for the submount structurization and therefore remains intact to form a good bonding with the oxide on the surface of the optical component