High purity ethylenediamine for semiconductor applications
A method for making the EDA that is suitable for use in thin-film semiconductor processing applications, are disclosed. The EDA is purified to remove water and trace metals. Water levels below about 50 ppm by weight are achieved by passing liquid through 3A type molecular sieve in a packed bed. Metallic impurities are removed by distillation and the resulting product is packaged in specially dried and optionally pre-conditioned containers.
1. A method for treating an ethylenediamine composition comprising:
contacting the ethylenediamine composition with a molecular sieve comprising type 3A zeolite under conditions sufficient to reduce the amount of water in the ethylenediamine composition to greater than 1 ppm and less than about 50 ppm;
distilling the ethylenediamine composition under conditions sufficient to reduce an amount of each of aluminum, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, titanium, and zinc to less than about 100 ppb, and
recovering an ethylenediamine product that is greater than about 99.9 weight percent pure;
wherein the contacting is carried out by passing the ethylenediamine composition in a liquid through a packed bed comprising the molecular sieve.
2. The method of claim 1 , wherein the ethylenediamine product contains less than about 50 ppb each of aluminum, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, titanium and zinc.
3. The method of claim 1 , wherein the ethylenediamine product contains less than about 10 ppm of water.
4. The method of claim 1 , wherein the ethylenediamine product contains less than about 5 ppm of water.
5. The method of claim 1 , wherein the ethylenediamine product contains less than about 5 ppm of halides.
6. The method of claim 1 , wherein the halide is chlorine.
7. The method of claim 1 , wherein the ethylenediamine product contains less than about 5 ppb of alkali metals.
8. The method of claim 1 , wherein the alkali metal is sodium.
9. The method of claim 1 , wherein the contacting comprises passing the ethylenediamine composition through a bed of the molecular sieve at a pressure that ranges from 1˜15 psi and at a temperature that ranges from 10˜35° C.
10. The method of claim 1 , wherein contacting the ethylenediamine composition with a molecular sieve takes place at a weight hourly space velocity (WHSV) of 0.1 to 10 h −1 .
11. The method of claim 10 , wherein contacting the ethylenediamine composition with a molecular sieve takes place at a weight hourly space velocity (WHSV) of 0.2 to 5 h −1 .