The disclosure provides a transistor, a method for manufacturing the transistor, and a semiconductor chip comprising the transistor. The transistor comprises: an active area, a gate stack, a primary spacer, and source/drain regions, wherein the active area is on a semiconductor substrate; the gate stack, the primary spacer, and the source/drain regions are on the active area; the primary spacer surrounds the gate stack; the source/drain regions are embedded in the active area and self-aligned with opposite sides of the primary spacer. Wherein the transistor further comprises: a silicide spacer, wherein the silicide spacer is located at opposite sides of the primary spacer, and a dielectric material is filled between the two ends of the silicide spacer in the width direction of the gate stack, so as to isolate the source/drain regions from each other.