The correct answer is: D. It is a 3 : 1 to 5 : 1 mix of sulphuric acid and hydrogen peroxide that is used to clean wafers of organic and metal contaminants or photo resist after metal patterning.
Piranha solution is a mixture of sulfuric acid and hydrogen peroxide that is used to clean silicon wafers. It is a powerful oxidizing agent that can remove organic and metal contaminants from the surface of the wafer. Piranha solution is also used to etch silicon dioxide, which is the material that is used to create the oxide layer on silicon wafers.
Piranha solution is a very dangerous chemical and should be handled with extreme care. It is corrosive and can cause serious burns if it comes into contact with skin or eyes. Piranha solution should always be stored in a cool, dark place and should never be mixed with other chemicals.
Here is a brief explanation of each option:
A. It is a 3 : 1 to 5 : 1 mix of nitric acid and hydrogen peroxide that is used to develop the oxide layer on silicon substrate. This is not correct. Piranha solution is a mixture of sulfuric acid and hydrogen peroxide, not nitric acid.
B. It is a 3 : 1 to 5 : 1 mix of sulphuric acid and hydrofluoric acid that is used to clean silicon wafers removing organic and metal contaminants or photo resist after metal patterning. This is not correct. Piranha solution is a mixture of sulfuric acid and hydrogen peroxide, not hydrofluoric acid.
C. It is a 3 : 1 to 5 : 1 mix of sulphuric acid and hydrogen peroxide that is used to grow the oxide layer on the silicon. This is not correct. Piranha solution is a powerful oxidizing agent that can remove organic and metal contaminants from the surface of the wafer, but it cannot grow the oxide layer on the silicon.
D. It is a 3 : 1 to 5 : 1 mix of sulphuric acid and hydrogen peroxide that is used to clean wafers of organic and metal contaminants or photo resist after metal patterning. This is correct. Piranha solution is a powerful oxidizing agent that can remove organic and metal contaminants from the surface of the wafer. It is also used to etch silicon dioxide, which is the material that is used to create the oxide layer on silicon wafers.