Semiconductor wet etchant and method of forming interconnection structure using the same

Abstract

A semiconductor wet etchant includes deionized water, a fluorine-based compound, an oxidizer and an inorganic salt. A concentration of the fluorine-based compound is 0.25 to 10.0 wt % based on a total weight of the etchant, a concentration of the oxidizer is 0.45 to 3.6 wt % based on a total weight of the etchant, and a concentration of the inorganic salt is 1.0 to 5.0 wt % based on a total weight of the etchant. The inorganic salt comprises at least one of an ammonium ion (NH 4 + ) and a chlorine ion (Cl − ).

1 . A method of forming a semiconductor device, comprising:
 providing a semiconductor substrate; and   treating the semiconductor substrate using a chemical solution comprising deionized water, and a fluorine-based compound, an oxidizer and an inorganic salt mixed in the deionized water,   wherein a concentration of the fluorine-based compound is 0.25 to 10.0 wt % based on a total weight of the chemical solution, a concentration of the oxidizer is 0.45 to 3.6 wt % based on a total weight of the chemical solution, and a concentration of the inorganic salt is 1.0 to 5.0 wt % based on a total weight of the chemical solution, and   wherein the inorganic salt comprises at least one of an ammonium ion (NH 4   + ) and a chlorine ion (Cl − ).   
     
     
         2 . The method according to  claim 1 , wherein the fluorine-based compound comprises at least one of fluorine hydride (HF), ammonium fluoride (NH 4 F), ammonium bifluoride (NH 4 HF 2 ), tetra-methyl ammonium fluoride (TMAF; (CH 3 ) 4 NF) and tetra-butyl ammonium fluoride (TBMA; (CH 3 CH 2 CH 2 CH 2 ) 4 NF). 
     
     
         3 . The method according to  claim 1 , wherein the oxidizer comprises at least one of hydrogen peroxide (H 2 O 2 ), nitric acid (HNO 3 ), sulphuric acid (H 2 SO 4 ), ammonium nitrate (NH 4 NO 3 ), ammonium iodate (NH 4 IO 3 ) and ammonium disulfate ((NH 4 ) 2 S 2 O 5 ). 
     
     
         4 . The method according to  claim 1 , wherein the inorganic salt comprises the ammonium ion (NH 4   + ), and wherein a non-metal atom is bonded to the ammonium ion (NH 4   + ). 
     
     
         5 . The method according to  claim 4 , wherein the non-metal atom is selected from the group consisting of chlorine (Cl), bromine (Br), Iodine (I) and carbonic acid (CO 3 ). 
     
     
         6 . The method according to  claim 1 , wherein the inorganic salt comprises the chlorine ion (Cl − ), and wherein a metal atom is bonded to the chlorine ion (Cl − ). 
     
     
         7 . The method according to  claim 6 , wherein the metal atom is selected from the group consisting of sodium (Na), kalium (K), calcium (Ca) and cesium (Cs). 
     
     
         8 . The method according to  claim 1 , wherein the inorganic salt comprises both the ammonium ion (NH 4   + ) and the chlorine ion (Cr), wherein a non-metal atom is bonded to the ammonium ion (NH 4   + ), and a metal atom is bonded to the chlorine ion (Cl − ). 
     
     
         9 . The method according to  claim 8 , wherein the non-metal atom is selected from the group consisting of chlorine (Cl), bromine (Br), Iodine (I) and carbonic acid (CO 3 ), and the metal atom is selected from the group consisting of sodium (Na), kalium (K), calcium (Ca) and cesium (Cs). 
     
     
         10 . The method according to  claim 1 , further comprising a non-ionic surfactant mixed in the deionized water, wherein the surfactant is a co-polymer of ethylene and propylene. 
     
     
         11 . The method according to  claim 1 , wherein the semiconductor substrate includes a device-forming region and a device-excluding region surrounding the device-forming region on one surface thereof. 
     
     
         12 . The method according to  claim 11 , the chemical solution is applied to the device-excluding region. 
     
     
         13 . The method according to  claim 11 , wherein the semiconductor substrate includes an insulating layer, a first metal layer and a second metal layer which are sequentially stacked,
 wherein the insulating layer and the first metal layer extend from the device-forming region toward the device-excluding region, and   wherein the second metal layer is on the device-forming region.   
     
     
         14 . The method according to  claim 13 , wherein the chemical solution is applied to the insulating layer and the first metal layer formed around the device-forming region. 
     
     
         15 . The method according to  claim 11 , wherein the semiconductor substrate includes an insulating layer, a first metal layer and a second metal layer which are sequentially stacked,
 wherein the insulating layer and the first metal layer cover the one surface and the other surface around the one surface, and   wherein the second metal layer covers the device-forming region.   
     
     
         16 . The method according to  claim 15 , wherein the treating of the semiconductor substrate using the chemical solution includes spraying the chemical solution on the insulating layer and the first metal layer covering the other surface to etch the insulating layer and the first metal layer on the other surface and expose the semiconductor substrate on the other surface. 
     
     
         17 . A method of forming a semiconductor device, comprising:
 preparing a semiconductor substrate including a main surface, a back surface opposite the main surface and a side surface connecting the main and back surfaces,   forming a material layer on the semiconductor substrate, the material layer covering the main surface, the side surface and the back surface; and   spraying a chemical solution on the material layer, the chemical solution being applied on at least the side surface and the back surface, and the chemical solution comprising deionized water, and a fluorine-based compound, an oxidizer and an inorganic salt mixed in the deionized water,   wherein a concentration of the fluorine-based compound is 0.25 to 10.0 wt % based on a total weight of the chemical solution, a concentration of the oxidizer is 0.45 to 3.6 wt % based on a total weight of the chemical solution, and a concentration of the inorganic salt is 1.0 to 5.0 wt % based on a total weight of the chemical solution, and   wherein the inorganic salt comprises at least one of an ammonium ion (NH 4   + ) and a chlorine ion (Cl − ).   
     
     
         18 . The method according to  claim 17 , wherein the material layer includes a lower layer and an upper layer, and the upper layer is on a center region of the main surface, and the lower layer is exposed from the upper layer. 
     
     
         19 . The method according to  claim 18 , wherein the upper layer includes conductive material, and the lower layer includes conductive and insulating materials. 
     
     
         20 . The method according to  claim 18 , wherein the spraying of the chemical solution on the material layer includes etching the lower layer on the remaining region surrounding the central region in the main surface, the side surface and the back surface.