摘要:
A method for form an integrated circuit device begins by growing a tunnel oxide (22). The tunnel oxide is exposed to a nitrogen containing ambient whereby nitrogen is incorporated at atomic locations at the interface between the tunnel oxide (22) and a substrate (11). This tunnel oxide and nitrogen exposure is performed for all of a floating gate active area (12), a high voltage active area (14) and a logic gate active area (16). A floating gate electrode (24) and interpoly dielectric regions (26 through 30) are then formed in the floating gate region (12). The tunnel oxide (22) is etched from the active areas (14 and 16) whereby nitrogen contamination (32) may remain. An optional sacrificial oxidation and a low temperature 830.degree. C. wet oxidation process utilizing HCL, H2 and O2 is then used to grow a high voltage gate dielectric (34) which has been shown to improve charge to breakdown characteristics by a factor of 1,000. After the formation of the high voltage gate oxide (34), a lower voltage logic gate oxide (36) is then formed.
摘要:
A stack of oxide (16) and silicon nitride (18) is grown/deposited over a patterned polysilicon line, which typically acts as a bottom capacitor plate. A thin layer of amorphous or polycrystalline silicon (20) is deposited over the blanket silicon nitride film. The thickness of the deposited silicon layer must be optimized according to the final amount of oxide desired over the silicon nitride, which will be roughly twice the thickness of the deposited silicon film. The oxide/nitride/silicon stack is then patterned and etched, stopping either at or underneath the bottom oxide. Any subsequent cleaning in potentially oxide-etching chemistries (including HF) is done with the protective silicon deposit on top of the silicon nitride. The entire structure is then thermally oxidized, transforming the deposited silicon into silicon oxide (30). Where the structure has been cleared down to the substrate by etching, a second gate oxide is simultaneously formed.
摘要:
A process of forming a device with nanoclusters. The process includes forming nanoclusters (e.g. silicon nanocrystals) and forming an oxidation barrier layer over the nanoclusters to inhibit oxidizing agents from oxidizing the nanoclusters during a subsequent formation of a dielectric of the device. At least a portion of the oxidation barrier layer is removed after the formation of the dielectric. In one example, the device is a memory wherein the nanoclusters are utilized as charge storage locations for charge storage transistors of the memory. In this example, the oxidation barrier layer protects the nanoclusters from oxidizing agents due to the formation of gate dielectric for high voltage transistors of the memory.