A multi-wafer based semiconductor light absorption structure comprising: a first wafer bonded with a second wafer , wherein the first wafer comprises: a photodiode comprising a light absorption region; a contact region, immediately above the light absorption region and in physical contact with the light absorption region; a first mirror region, wherein the light absorption region is located in between the first mirror region and the contact region, wherein the first mirror region is a metal mirror and is connected to the light absorption region via a first contact metal; and a second mirror region, wherein the contact region is located in between the second mirror region and the light absorption region, wherein the second mirror region is a dielectric mirror; a bonding interface between the first wafer and the second wafer , wherein the bonding interface is located below the light absorption region and is not in physical contact with the light absorption region ; wherein a CMOS integrated circuit comprises at least one CMOS transistor and is located in the second wafer , wherein the CMOS integrated circuit is coupled to the contact region via vertical contact vias in the first wafer and the bonding interface; wherein each vertical contact via is provided by a second contact metal in electrical contact with the contact region and a bond pad electrically connected to the CMOS integrated circuit ; and wherein the bonding interface uses a metal-plus-dielectric bond to bond the first wafer and the second wafer together and to provide an electrical connection between the bond pad and the CMOS integrated circuit , and between the first mirror region and the CMOS integrated circuit . a first wafer bonded with a second wafer , wherein the first wafer comprises: a photodiode comprising a light absorption region; a contact region, immediately above the light absorption region and in physical contact with the light absorption region; a first mirror region, wherein the light absorption region is located in between the first mirror region and the contact region, wherein the first mirror region is a metal mirror and is connected to the light absorption region via a first contact metal; and a second mirror region, wherein the contact region is located in between the second mirror region and the light absorption region, wherein the second mirror region is a dielectric mirror; a photodiode comprising a light absorption region; a contact region, immediately above the light absorption region and in physical contact with the light absorption region; a first mirror region, wherein the light absorption region is located in between the first mirror region and the contact region, wherein the first mirror region is a metal mirror and is connected to the light absorption region via a first contact metal; and a second mirror region, wherein the contact region is located in between the second mirror region and the light absorption region, wherein the second mirror region is a dielectric mirror; a bonding interface between the first wafer and the second wafer , wherein the bonding interface is located below the light absorption region and is not in physical contact with the light absorption region ; wherein a CMOS integrated circuit comprises at least one CMOS transistor and is located in the second wafer , wherein the CMOS integrated circuit is coupled to the contact region via vertical contact vias in the first wafer and the bonding interface; wherein each vertical contact via is provided by a second contact metal in electrical contact with the contact region and a bond pad electrically connected to the CMOS integrated circuit ; and wherein the bonding interface uses a metal-plus-dielectric bond to bond the first wafer and the second wafer together and to provide an electrical connection between the bond pad and the CMOS integrated circuit , and between the first mirror region and the CMOS integrated circuit . <EOS>