Method for forming integrated circuits with aligned (100) NMOS and (110) PMOS FinFET sidewall channels

A method of fabricating an integrated circuit, comprising:

• providing a direct silicon bonded (DSB) hybrid orientation technology (HOT) substrate including an upper silicon layer having a top surface with one of a (100) or (110) crystal orientation directly bonded over a lower silicon substrate having a top surface with the other of the (100) or (110) crystal orientation;
• amorphizing a region of the upper silicon layer;
• regrowing and recrystallizing the amorphized region of the upper silicon layer using the crystalline structure of the lower silicon substrate as a template, thereby giving the recrystallized region a top surface with the other crystal orientation;
• patterning the regrown and recrystallized region of the upper silicon layer to form a first fin having a top surface with the other crystal orientation and a sidewall surface with the one crystal orientation;
• and
• patterning an unamorphized region of the upper silicon layer to form a second fin having a top surface with the one crystal orientation and a sidewall surface with the other crystal orientation;
• wherein the first fin sidewall surface defines a channel with a first carrier flow direction for a first FinFET, the second fin sidewall defines a channel with a second carrier flow direction for a second FinFET, and the second carrier flow direction is parallel or perpendicular to the first carrier flow direction.

A method of fabricating an integrated circuit, comprising:

• providing a direct silicon bonded (DSB) hybrid orientation technology (HOT) substrate including an upper silicon layer having a top surface with a (110) crystal orientation directly bonded over a lower silicon substrate having a top surface with a (100) crystal orientation;
• amorphizing a region of the upper silicon layer;
• regrowing and recrystallizing the amorphized region of the upper silicon layer using the crystalline structure of the lower silicon substrate as a template, thereby giving the regrown and recrystallized region a top surface with the (100) crystal orientation;
• patterning the regrown and recrystallized region of the upper silicon layer to form a first fin having a top surface with the (100) crystal orientation and a sidewall surface with the (110) crystal orientation;
• and
• patterning an unamorphized region of the upper silicon layer to form a second fin having a top surface with the (110) crystal orientation and a sidewall surface with the (100) crystal orientation;
• wherein the first fin sidewall surface defines a channel with a current flow direction for a PMOS FinFET, the second fin sidewall defines a channel with current flow direction for an NMOS FinFET, and the second current flow direction is parallel to the first current flow direction.