Microelectronic assemblies with anchor layer around a bridge die

A microelectronic assembly, comprising:

• a first layer of a substrate having a cavity;
• a first die at least partially nested in the cavity in the first layer of the substrate, the first die having a surface with conductive contacts;
• a liner layer on the first layer, in a portion of the cavity, and on and around the first die, wherein a material of the liner layer includes:
• silicon or aluminum, and one or more of nitrogen, oxygen, and carbon;
• a second layer on the liner layer, wherein the second layer extends into the cavity and is on and around the first die;
• and
• a second die on the second layer, wherein the second die is electrically coupled to the conductive contacts on the first die by conductive vias through the second layer and the liner layer.

A microelectronic assembly, comprising:

• a substrate having first conductive contacts and second conductive contacts at a surface of the substrate;
• a first microelectronic component having third conductive contacts and fourth conductive contacts at a face of the first microelectronic component, wherein the third conductive contacts are coupled to the first conductive contacts;
• a second microelectronic component having fifth conductive contacts and sixth conductive contacts at a face of the second microelectronic component, wherein the fifth conductive contacts are coupled to the second conductive contacts;
• and
• a bridge component having seventh conductive contacts and eighth conductive contacts at a face of the bridge component;
• wherein the substrate further includes:
• a first dielectric material having a cavity and the bridge component is at least partially nested in the cavity;
• a second dielectric material on the first dielectric material and on and around the bridge component;
• a liner between the first dielectric material and the second dielectric material and between the bridge component and the second dielectric material, a material of the liner including silicon or aluminum, and one or more of nitrogen, oxygen, and carbon;
• and
• conductive vias through the liner and second dielectric material electrically coupling the fourth conductive contacts to the seventh conductive contacts and the sixth conductive contacts to the eighth conductive contacts.