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AssigneeKoninklijke Philips Electronics N.V.
InventorsJurriaan Schmitz, Franciscus Petrus Widdershoven, Michiel Slotboom
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A method of manufacturing a semiconductor device comprising a non-volatile memory with memory cells (Mij) including a select transistor (T1) with a select gate (1) and including a memory transistor (T2) with a floating gate (2) and a control gate (3). In a semiconductor body (10), active semiconductor regions are formed which are mutually insulated by field oxide regions (12). Next, the surface (11) is provided with a gate oxide layer (14) and a first layer of a conductive material wherein the select gate (1) is etched. Subsequently, the walls of the select gate extending perpendicularly to the surface are provided with an isolating material (17). The gate oxide next to the select gate is replaced by a layer of tunnel oxide (18). Next, a second layer of a conductive material (21), an interlayer dielectric (25) and a third layer of a conductive material (26) are deposited. The control gate (3) extending above and next to the select gate is formed in the third layer. Using the control gate as a mask, the floating gate (2) is subsequently etched in the second layer of conductive material. In this method, the second layer is deposited in a larger thickness than the select gate, after which this layer is planarized prior to the deposition of the interlayer dielectric and the third layer of conductive material. In this manner, a compact memory cell can be manufactured.
A method of manufacturing a semiconductor device comprising a non-volatile memory with memory cells including a select transistor with a select gate and including a memory transistor with a floating gate and a control gate, in which method active semiconductor regions are formed in a semiconductor body, which active semiconductor regions border on a surface of said semiconductor body and are mutually insulated by field oxide, after which the surface is provided with a layer of gate oxide and a first layer of a conductive material, wherein the select gate is etched, after which the select gate is provided, on its side walls extending transversely to the surface, with an insulating material, and the gate oxide next to the select gate is removed and substituted with a layer of a tunnel oxide, whereafter a second layer of a conductive material, a layer of an intermediate dielectric and a third layer of a conductive material are deposited, in which third layer of conductive material the control gate is formed which extends above and next to the select gate, whereafter the floating gate is etched in the second layer of conductive material, using the control gate as a mask, characterized in that the second layer of conductive material is deposited in a thickness that exceeds the thickness of the select gate, whereafter this layer of conductive material is planarized before the layer of intermediate dielectric and the third layer of conductive material are deposited.
Dependencies are inferred from the claim text.