Semiconductor Manufacture Employing Isopropanol Drying
This invention is directed to an improvement in a wet chemical process for producing electronic precursors. In such process a silicon surface is treated with a wet chemical and the wet chemical subsequently removed therefrom by contact with a drying vapor. In this case, the improvement in the process comprises: employing a drying vapor comprised of isopropanol; and, maintaining the isopropanol employed in said drying vapor at a temperature below about 80° F. prior to forming said drying vapor. Preferably the isopropanol is maintained free from exposure to light from the time of manufacture to the time of use.
1 . A wet chemical process for producing electronic devices comprising:
treating a semiconductor substrate with a wet chemical;
obtaining liquid isopropanol;
forming a drying vapor comprising isopropanol from the liquid isopropanol;
removing the wet chemical from the semiconductor substrate by contact with the drying vapor;
and maintaining the liquid isopropanol at a temperature in the range of 80° F. and below for the duration of time between obtaining the liquid isopropanol and forming said drying vapor therefrom.
2 . The process of claim 1 further comprising maintaining the liquid isopropanol in an environment substantially free from exposure to light prior to forming said drying vapor therefrom.
3 . The process of claim 1 wherein the temperature of the liquid isopropanol is maintained at a temperature in the range of 72° F. and below prior to forming said drying vapor therefrom.
4 . A wet chemical process for processing semiconductor substrates having a surface, the process comprising:
treating the surface of the substrate with a wet chemical; and
removing the wet chemical from the surface of the substrate by contact with a drying vapor comprising isopropanol, wherein the drying vapor is formed from liquid isopropanol, and
wherein the liquid isopropanol has been shipped in transport using refrigeration such that the liquid isopropanol is maintained at a temperature in the range of 80° F. and below during the transport.
5 . The process of claim 4 wherein the liquid isopropanol shipped in said transport is stored in a warehouse prior to use and the warehouse is equipped with sufficient air conditioning to maintain the liquid isopropanol at a temperature in the range of 80° F. and below.
6 . The process of claim 5 wherein the liquid isopropanol is maintained at a temperature in the range of 72° F. and below.
7 . The process of claim 5 wherein, in the wet chemical process, the surface of the substrate is rinsed with water prior to contact with said drying vapor.
8 . A wet chemical process for producing electronic devices manufactured from semiconductor substrates using comprising:
treating a surface of the substrate with a wet chemical;
rinsing the wet chemical from the surface with water;
removing the water from the surface by contact with a drying vapor comprising isopropanol, wherein the drying vapor is formed from liquid isopropanol; and
employing liquid isopropanol that has been maintained at a temperature in the range of from 55° F. to 80° F. from the point of manufacture of the liquid isopropanol until formation of drying vapor therefrom.
9 . The method of claim 8 wherein the liquid isopropanol has been shipped, stored, or both following manufacture, and wherein the temperature of the ambient environment through which the liquid isopropanol has been shipped, in which the liquid isopropanol has been stored, or both may, at times, exceed 100° F.
10 . The process of claim 1 , wherein the liquid isopropanol is substantially free of peroxide.
11 . A wet chemical process for producing electronic devices comprising:
treating a semiconductor substrate with a wet chemical;
forming a drying vapor comprising isopropanol from liquid isopropanol, wherein the liquid isopropanol is substantially free from peroxide; and
removing the wet chemical from the semiconductor substrate by contact with the drying vapor.
12 . The process of claim 11 , further comprising preventing the formation of peroxide from the liquid isopropanol.