Method for transferring chips onto a substrate

Method for making a stack of at least two stages of circuits, each stage comprising a substrate and at least one component and metallic connections formed in or on this substrate, the assembly of a stage to be transferred onto a previous stage comprising:

• a) ionic implantation in the substrate of the stage to be transferred through a surface of this substrate, said implantation surface and through at least part of the components, so as to form a weakened zone under the components of this substrate,
• b) then formation of metallic connections of said components in this substrate between each other and/or in order to connect these components to other components, with a thermal budget for which the temperature is equal to approximately 400° C. for a duration of about 1 h 30 min,
• c) then transfer and assembly of part of this substrate, comprising components or groups of components, through its implantation surface onto the previous stage,
• d) then a step to thin the transferred part of said substrate by fracture along the weakened zone, with a thermal budget for which the temperature is equal to approximately 450° C. for a duration of about 2 h 00.

Method for making a stack of at least two stages of circuits, each stage comprising a substrate and at least one component and metallic connections formed in or on this substrate, components in a stage to be transferred comprising a substrate and CMOS transistors, the assembly of said stage to be transferred onto a previous stage comprising:

• a) planarising a dielectric that covers the substrate of said stage to be transferred;
• b) then ionic implantation in the substrate of the stage to be transferred through a surface of this substrate, said implantation surface and through at least part of the components, so as to form a weakened zone under the components of this substrate,
• c) then forming contact pads of the CMOS transistor sources, drains and gates;
• d) then formation of metallic connections of said components in this substrate between each other and/or in order to connect these components to other components,
• e) then transfer and assembly of part of this substrate, comprising components or groups of components, through its implantation surface onto the previous stage,
• f) then a step to thin the transferred part of said substrate by fracture along the weakened zone.