Thermal-oxidative production process of semiconductor wafer

Abstract

The thermal oxidation process for making semiconductor wafer includes the following steps: under the condition of the temp. lower than thermal oxidation temp. placing the wafer into furnace tube, introducing large flow quantity of nitrogen gas or argon gas to remove water content and oxygen gas being in the furnace tube, then filling the furnace tube with wafers, progressively heating the furnace tube to main thermal oxidation operation temp., and continuously introducing nitrogen gas or argon gas, then introducing oxygen gas under the condition of said operation temp. to implement thermal oxidation process, and then lowering operation temp. progressively and taking out the wafers.

Description

technical field [0001] The present invention relates to a manufacturing process of a semiconductor device, and in particular to a thermal oxidation manufacturing process of a semiconductor wafer. Background technique [0002] In the traditional manufacturing process of semiconductor devices, after the memory devices are formed on the semiconductor wafer, an oxidation process is performed on the semiconductor wafer to form an oxide layer on the semiconductor wafer, and the formed The oxide layer protects the memory devices on the semiconductor wafer. [0003] Known methods for forming an oxide layer on a semiconductor wafer, such as the method of thermally oxidizing the wafer in a furnace tube, for memory devices, the above-mentioned oxidation process can be used in the formation of gate structures and source regions / After the drain region, a storage cell re-oxidation layer (Cell re-oxide) is formed on the entire surface of the gate structure and the substrate. The main fun...

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Problems solved by technology

[0006] When it is desired to form the memory cell of the re-oxidation layer of the memory cell, such as a mask-type read-only memory cell, and form a metal silicide layer on the gate structure of the mask-type read-only memory cell, at the stage where the wafer is loaded into the furnace tube , due to the high humidity (moisture) and oxygen content in the furnace tube, the silicon component of the metal silicide layer will react with oxygen in advance during the loading stage, so after the wafer passes through the entire hot furnace tube oxidation reaction, The thickness of the silicon oxide layer in the silicided metal layer will be higher than the thickness of the rest of the silicon oxide layer, and protrusions will be formed on the wafer, causing defects.

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