Etchant compositions and methods of manufacturing integrated circuit devices using the same
Etchant compositions described herein include etchant compositions for etching a silicon film and may include nitric acid, fluoric acid, phosphoric acid, acetic acid, a nitrogen compound, and water. The nitrogen compound may include fluorine (F), phosphorus (P), and/or carbon (C). Also described are methods of manufacturing an integrated circuit (IC) device. The methods may include providing a structure in which a silicon film doped at a first dopant concentration and an epitaxial film doped at a second dopant concentration are stacked. The second dopant concentration may be different from the first dopant concentration. The silicon film may be selectively etched from the structure by using an etchant composition.
1. An etchant composition consisting essentially of: nitric acid in an amount of 10% to 20% by weight of the etchant composition; fluoric acid in an amount of 1% to 15% by weight of the etchant composition; phosphoric acid in an amount of 5% to 30% by weight of the etchant composition;
acetic acid in an amount of 10% to 50% by weight of the etchant composition; a nitrogen compound in an amount of 0.5% to 10% by weight of the etchant composition; and
water;
wherein the nitrogen compound comprises ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, urea, urea phosphate, urea nitrate, imidazolidinyl urea, phenylurea, 1,1-diphenyl urea, 1,3-diphenyl urea, hydroxyurea, 1,1-dimethyl urea, or a combination thereof.
2. The etchant composition of claim 1 , wherein the nitrogen compound comprises ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, or a combination thereof.
3. The etchant composition of claim 1 , wherein the nitrogen compound comprises urea, urea phosphate, urea nitrate, imidazolidinyl urea, phenylurea, 1,1-diphenyl urea, 1,3-diphenyl urea, hydroxyurea, 1,1-dimethyl urea, or a combination thereof.
4. The etchant composition of claim 1 , wherein the etchant composition is configured to etch a single-crystalline silicon film doped with a P-type dopant.
5. The etchant composition of claim 1 , wherein the etchant composition is configured to etch a silicon film that is doped with boron (B) atoms at a concentration of 1.0×10 17 atoms/cm 3 to 5.0×10 18 atoms/cm 3 .
6. The etchant composition of claim 1 , wherein a weight percent of the nitrogen compound is lower than a weight percent of each of the nitric acid, the fluoric acid, the phosphoric acid, and the acetic acid.
7. The etchant composition of claim 1 , wherein each of a weight percent of the nitric acid, a weight percent of the phosphoric acid, and a weight percent of the acetic acid is at least twice a weight percent of the nitrogen compound.
8. The etchant composition of claim 1 , wherein a weight percent of the nitric acid is lower than a weight percent of the acetic acid.