Patent ID: 11251049

Abstract:
In an etching method, a target object temperature is maintained within a range from −30° C. to 30° C. When a flow rate of an ith fluorocarbon gas in one or multiple fluorocarbon gases is referred to as J(i); a number of fluorine atoms and a number of carbon atoms in the corresponding gas are referred to as M(i) and N(i), respectively; a value calculated by summing J(i)×N(i)/M(i) of all values that i can be is referred to as Ua; a flow rate of a kth hydrogen-containing gas in one or multiple hydrogen-containing gases is referred to as J(k); a number of hydrogen atoms in the corresponding gas is referred to as H(k); and a value calculated by summing J(k)×H(k) of all values that k can be is referred to as Ub, Ua/Ub satisfies a condition of 0.04<Ua/Ub<0.22.