Back end of line process integrated optical device fabrication

A method of integrated optical device fabrication forming an optical device within a vertical span of a metal stack of an integrated semiconductor chip as part of a back end of line fabrication process, comprising:

• providing a substrate;
• providing a device layer including at least one optical device on the substrate;
• depositing a first oxide layer over the semiconductor devices;
• forming a first metal via through the first oxide layer into contact with the device layer;
• depositing a second oxide layer comprising an oxide material over the first oxide layer;
• etching a first portion of the second oxide layer;
• depositing metal in the first portion of the second oxide layer for connection with the first metal via and external contacts;
• forming a second portion of the second oxide layer into a first waveguide for coupling light to or from the at least one optical device.

A method of integrated optical device fabrication forming an optical device within a vertical span of a metal stack of an integrated semiconductor chip as part of a back end of line fabrication process, comprising:

• providing a substrate;
• providing a device layer including at least one integrated optical device on the substrate;
• depositing a first oxide layer over the semiconductor devices;
• forming a first metal via through the first oxide layer into contact with the device layer;
• depositing a first stop layer over the first oxide layer;
• depositing a second oxide layer comprising an oxide material over the first stop layer;
• etching a first portion of the second oxide layer down to the first stop layer;
• depositing metal in the first portion of the second oxide layer for connection with the first metal via and external contacts;
• forming a portion of the first stop layer into a first waveguide for coupling light to or from the at least one integrated optical device.

An integrated semiconductor device, comprising:

• a substrate;
• a device layer on the substrate;
• a first oxide layer over the device layer;
• a second oxide layer over the first oxide layer;
• a third oxide layer over the second oxide layer;
• a fourth oxide layer over the third oxide layer;
• a fifth oxide layer over the fourth oxide layer
• a metal stack for connection with external contacts, including a first metal portion in a first portion of the second oxide layer extending between the first and third oxide layers, and a first metal via extending between the first metal portion and the device layer, and a second metal portion in a first portion of the fourth oxide layer extending between the third and fifth oxide layers, and a second metal via extending between the second metal portion and the device layer;
• an optical coupler including a first waveguide in a second portion of the third oxide layer, and a second waveguide in a second portion of the fifth oxide layer for coupling light to or from the at least one device layer.