Referring now to FIG. 1G, a portion of the ESL 160 situated on the bottom of the opening 180 is removed using another etching process. This etching process may include wet etching or dry etching, and etches the ESL 160 faster than surrounding materials. As a result, the opening 180 is extended to the upper surface of the conductive component 120. In some embodiments, a middle ESL portion 142, which is situated below the opening 180, is also partially etched away by the etching process. When the middle ESL portion 142 and the ESL 160 are the same material (as deposited), a duration of the etching process is controlled such that the middle ESL portion 142 is not fully etched. Otherwise, when the middle ESL portion 142 and the ESL 160 are different materials (as deposited), the etching process may have a relatively lower etch rate on the ESL portion 142 (but an upper corner of the middle ESL portion 142 may still get chipped away as illustrated in FIG. 1G). In any case, the etching process ensures that the opening 180 does not reach the ILD 130.