Selective hydrophobic layer removal using UV irradiation with non-aligned mask

A device comprising:

• a semiconductor device;
• and
• a wafer device with a first side and a second side, wherein the first side is opposite of the second side, wherein the semiconductor device is formed on the first side of the wafer device that forms at least a cavity between semiconductor device and the wafer device, and wherein an opening of the cavity faces away from the semiconductor device and is positioned on the second side of the wafer device, wherein the second side of the wafer device includes a first portion and a second portion wherein the first portion of the second side is coated with a hydrophobic layer and wherein the hydrophobic layer is absent on the second portion of the second side,
• wherein the cavity, an interior of the semiconductor device, and an exterior of the semiconductor device are coated with the hydrophobic layer.

A method comprising:

• forming a microphone sensing device comprising a micro-electro-mechanical system (MEMS) device on a first side of a first portion of a wafer device and on the first side of a second portion of the wafer device, wherein the microphone sensing device and the first portion and the second portion of the wafer device forms a cavity with an opening of the cavity facing a second side of the first portion and the second portion of the wafer device that is opposite to that of the first side;
• forming a hydrophobic layer on the second side of the wafer device, on the cavity and on an interior of the microphone sensing device;
• forming a mask on the hydrophobic layer on the second side of the wafer device, wherein the mask is patterned that creates a plurality of perforation covering a portion of the hydrophobic layer on the second side of the wafer device and leaving another portion of the hydrophobic layer on the second side of the wafer device exposed;
• shining a light on to the second side of the wafer device, wherein the shining the light removes the another portion of the hydrophobic layer to expose the wafer device underneath the hydrophobic layer;
• and
• removing the mask, wherein the second side of the wafer device includes a first region and a second region, wherein the first region on the second side of the wafer device corresponds to the portion of the hydrophobic layer and is covered with the hydrophobic layer, and wherein the second region on the second side of the wafer device corresponds to the another portion of the hydrophobic layer on the second side that was removed leaving the second region on the second side of the wafer device exposed.