Reflective semiconductor device with mirror elements having two oxide layers over aluminum layer, and related method
A reflective semiconductor device includes an integrated circuit (IC) structure, and a pair of mirror elements over the IC structure. The pair of mirror elements are separated by a trench. Each mirror element includes a mirror layer of, for example, aluminum, on the IC structure, and a low temperature oxide (LTO) layer on the mirror layer. A high temperature oxide (HTO) layer is over the pair of mirror elements and fills the trench. A liquid crystal layer over the mirror elements provides a liquid crystal on semiconductor (LCOS) device. The two-oxide layer prevents mirror layer creep and/or agglomeration during formation of the HTO layer and provide a suitable surface for LCOS assembly without using specialized alloys.
1 . A reflective semiconductor device, comprising:
an integrated circuit (IC) structure;
a pair of mirror elements over the IC structure, the pair of mirror elements separated by a trench, each mirror element including:
a mirror layer on the IC structure, and
a low temperature oxide (LTO) layer on the mirror layer; and
a high temperature oxide (HTO) layer over the pair of mirror elements and filling the trench.
2 . The reflective semiconductor device of claim 1 , wherein the mirror layer consists essentially of aluminum.
3 . The reflective semiconductor device of claim 1 , wherein a surface of the HTO layer deviates no greater than 10 nanometers over the LTO layer versus in the trench between the pair of mirror elements.
4 . The reflective semiconductor device of claim 1 , wherein the mirror layer has a thickness of no greater than 50 nanometers, and the LTO layer and the HTO layer have a cumulative thickness of no greater than 100 nanometers over the mirror layer.
5 . The reflective semiconductor device of claim 1 , wherein the trench has a width of no greater than 100 nanometers.
6 . The reflective semiconductor device of claim 1 , wherein the LTO layer includes a silane-based silicon oxide (SiO 2 ), and the HTO layer includes a tetraethyl orthosilicate (TEOS) based silicon oxide (SiO 2 ).
7 . The reflective semiconductor device of claim 1 , wherein sidewalls of the LTO layer are aligned with sidewalls of the mirror layer, and the HTO layer abuts the sidewalls of the LTO layer and the mirror layer.
8 . The reflective semiconductor device of claim 1 , further comprising a liquid crystal layer disposed over the pair of mirror elements, and wherein the reflective semiconductor device is a liquid crystal on semiconductor (LCOS) device.
9 . A reflective semiconductor device, comprising:
an integrated circuit (IC) structure;
a pair of mirror elements over the IC structure, the pair of mirror elements separated by a trench, each mirror element including:
an aluminum layer on the IC structure, and
a low temperature oxide (LTO) layer over the aluminum layer; and
a high temperature oxide (HTO) layer over the pair of mirror elements and filling the trench,
wherein sidewalls of the LTO layer are aligned with sidewalls of the aluminum layer, and the HTO layer abuts the sidewalls of the LTO layer and the aluminum layer, and
wherein a surface of the HTO layer deviates no greater than 10 nanometers over the LTO layer versus in the trench between the pair of mirror elements.
10 . The reflective semiconductor device of claim 9 , wherein the aluminum layer has a thickness of no greater than 50 nanometers, and the LTO layer and the HTO layer have a cumulative thickness of no greater than 100 nanometers over the aluminum layer.
11 . The reflective semiconductor device of claim 9 , wherein the trench has a width of no greater than 100 nanometers.
12 . The reflective semiconductor device of claim 9 , wherein the LTO layer includes a silane-based silicon oxide (SiO 2 ), and the HTO layer includes a tetraethyl orthosilicate (TEOS) based silicon oxide (SiO 2 ).
13 . The reflective semiconductor device of claim 9 , further comprising a liquid crystal layer disposed over the pair of mirror elements, and the reflective semiconductor device is a liquid crystal on semiconductor (LCOS) device.