Sample well fabrication techniques and structures for integrated sensor devices
Methods of forming an integrated device, and in particular forming one or more sample wells in an integrated device, are described. The methods may involve forming a metal stack over a cladding layer, forming an aperture in the metal stack, forming first spacer material within the aperture, and forming a sample well by removing some of the cladding layer to extend a depth of the aperture into the cladding layer. In the resulting sample well, at least one portion of the first spacer material is in contact with at least one layer of the metal stack.
1. An integrated device comprising:
a cladding layer;
a metal stack formed over the cladding layer and having at least one undercut region;
a sample well extending through the metal stack proximate to the at least one undercut region and into the cladding layer; and
a first spacer material filling the at least one undercut region.
2. The integrated device of claim 1 , wherein the first spacer material forms at least one sidewall of the sample well.
3. The integrated device of claim 1 , wherein the first spacer material comprises one or more selected from the group of: amorphous silicon (α-Si), SiO 2 , SiON, and SiN.
4. The integrated device of claim 1 , wherein the first spacer material comprises one or more selected from the group of: TiO 2 , Al 2 O 3 , HfO 2 , TiN, ZrO 2 , and Ta 2 O 5 .
5. The integrated device of claim 1 , wherein the metal stack comprises at least one layer including aluminum and at least one layer including titanium.
6. The integrated device of claim 1 , wherein the cladding layer comprises SiO 2 .
7. The integrated device of claim 1 , further comprising a second spacer material in contact with one or more of the metal stack, the first spacer material, and the cladding layer.
8. The integrated device of claim 7 , wherein the second spacer material forms at least one sidewall of the sample well.
9. The integrated device of claim 7 , wherein the second spacer material comprises one or more layers selected from the group of: TiO 2 , Al 2 O 3 , HfO 2 , ZrO 2 , and Ta 2 O 5 .
10. The integrated device of claim 1 , wherein the metal stack comprises a first layer formed over a second layer, and the undercut region is formed in the second layer.