Substrates bonded with oxide affinity agent and bonding method

An electrical device comprising:

• first and second semiconductor wafers each including a plurality of integrated circuits;
• silicon on the first semiconductor wafer;
• and
• a bonding structure including gold alloyed with a material having a free energy lower than that of silicon dioxide, wherein the first semiconductor wafer is bonded to the second semiconductor wafer by the gold alloy that is bonded to the silicon on the first semiconductor wafer.

An electrical device comprising:

• first and second substrates each including a plurality of integrated circuits and the first substrate having a semiconductor layer thereon;
• a bonding structure having opposing ends respectively upon the semiconductor layer of the first substrate and the second substrate, the bonding structure including:
• a noble metal base layer upon the second substrate;
• an oxide affinity material in contact with the noble metal base layer and having an affinity for oxygen higher than that of the material of which the semiconductor layer is composed;
• and
• a noble metal interface between the oxide affinity material and the semiconductor layer, wherein the first substrate is bonded to the second substrate by the bonding structure.

An electrical device comprising:

• first and second semiconductor wafers each including a plurality of integrated circuits and the first semiconductor wafer have a silicon layer thereon;
• a bonding structure having opposing ends respectively on the silicon layer and the second semiconductor wafer, the bonding structure including:
• a gold base layer upon the first semiconductor wafer;
• an oxide affinity material in contact with the gold metal base layer and having an affinity for oxygen higher than that of silicon;
• and
• a gold interface between the oxide affinity material and with the silicon layer, wherein the first semiconductor wafer is bonded to the second semiconductor wafer by the bonding structure.

An electrical device comprising first and second semiconductor wafers each including a plurality of integrated circuits enclosed within a sealed region that is defined in part by a bonding structure bonding the first semiconductor wafer to the second semiconductor wafer and including:

• a silicon material;
• a gold base layer upon the silicon material;
• an oxide affinity material in contact with the gold metal base layer and having a free energy lower than that of silicon dioxide;
• and
• a noble metal interface on the oxide affinity material.

A substrate bonding method comprising the steps of:

• forming a plurality of integrated circuits in at least one of first and second substrates;
• forming a semiconductor layer on the first substrate;
• forming a noble metal base layer upon the second substrate;
• forming an oxide affinity material in contact with the noble metal base layer, the oxide affinity material having an affinity for oxygen higher than that of the material of which the semiconductor layer is composed;
• forming a noble metal interface upon the oxide affinity material;
• and
• pressing the semiconductor layer on the first substrate against the noble metal interface in order to:
• remove a native oxide on the semiconductor layer by diffusion into the noble metal interface and reaction with the oxide affinity material;
• and
• form a bond between the first and second substrates.