Microelectronic imagers with integrated optical devices and methods for manufacturing such microelectronic imagers

A method of fabricating optical devices for use in microelectronic imagers, each imager having an imaging unit including a first substrate, an image sensor on the first substrate and a peripheral zone around the image sensor, the first substrate being a semiconductive material, and the method comprising:

• etching a plurality of depressions in a first side of a second substrate, wherein individual depressions have a contour defining a lens curvature and the second substrate has a coefficient of thermal expansion at least approximately equal to that of glass, silicon, silicon nitride, silicon dioxide, or gallium arsenide;
• depositing an optics material layer onto the first side of the second substrate to fill the depressions;
• removing an upper portion of the optics material layer to form lenses defined by portions of the optics material layer remaining in the depressions;
• and
• etching compartments into a second side of the second substrate, wherein the compartments are aligned with corresponding lenses and each compartment has a sidewall configured to bound corresponding peripheral zones.

A method of fabricating optical devices for use in packaging a plurality of image sensors arranged in a die pattern on a first substrate, the method comprising:

• providing a second substrate having a first side, a second side, and a coefficient of thermal expansion at least approximately the same as that of the first substrate;
• etching a plurality of depressions in the first side of the second substrate, wherein individual depressions have a contour defining a lens curvature;
• depositing an optics material layer onto the first side of the second substrate to fill the depressions;
• removing an upper portion of the optics material layer to form lenses defined by portions of the optics material layer remaining in the depressions;
• and
• etching the compartments into the second side of the second substrate, wherein the compartments are aligned with corresponding lenses and are arranged in an optics pattern corresponding to the die pattern.

A method for packaging a plurality of microelectronic imagers at the wafer level, comprising:

• providing a first substrate having a front side, a backside and a plurality of image sensors at the front side;
• etching a plurality of depressions in a first side of a second substrate, wherein individual depressions have a contour defining a lens surface, and the second substrate has a coefficient of thermal expansion at least approximately the same as that of the first substrate;
• depositing an optics material layer onto the first side of the second substrate to fill the depressions;
• removing an upper portion of the optics material layer to form lenses defined by portions of the optics material layer remaining in the depressions;
• etching compartments into a second side of the second substrate, wherein the compartments are aligned with corresponding lenses and the compartments form part of stand-offs;
• and
• mounting the stand-offs to the front side of the first substrate, wherein the compartments are aligned with corresponding image sensors.