Flash and fabricating method of the same
AssigneeUnited Microelectronics Corp.
InventorsXiaojuan Gao, Chi Ren
Life of this patent
Estimating the term…
Abstract
A flash includes a substrate. Two gate structures are disposed on the substrate. Each of the gate structures includes a floating gate and a control gate. The control gate is disposed on the floating gate. An erase gate is disposed between the gate structures. Two word lines are respectively disposed at a side of each of the gate structures. A top surface of each of the word lines includes a first concave surface and a sharp angle. The sharp angle is closed to a sidewall of the word line which the sharp angle resided. The sidewall is away from each of the gate structures. The sharp angle connects to the first concave surface.
Claims9
A fabricating method of a flash, comprising:
- providing a substrate, wherein two gate structures are disposed on the substrate;
- forming a conductive layer conformally covering the gate structures and the substrate, wherein the conductive layer comprises a first mountain profile, a second mountain profile, a first flat profile and a second flat profile, the first mountain-like profile connects to the second mountain profile, the first flat profile is at one side of the first mountain profile, the second flat profile is at one side of the second mountain profile, the first mountain profile and the second mountain profile respectively cover one of the two gate structures, the first flat profile and the second flat profile cover the substrate, the first mountain profile and the second mountain profile respectively comprise a summit and two slopes;
- forming a sacrificial layer conformally covering the conductive layer;
- performing a first anisotropic etching process to remove the sacrificial layer on the summit of the first mountain profile, on the summit of the second mountain profile, on the first flat profile and on the second flat profile, and remaining the sacrificial layer on the two slopes of the first mountain profile and on the two slopes of the second mountain profile;
- and
- after the first anisotropic etching process, performing a second anisotropic etching process to etch the conductive layer and the sacrificial layer until the first flat profile and the second flat profile being entirely removed.
Dependencies are inferred from the claim text.