Positive temperature coefficient polycrystalline silicon resistor structure and manufacturing method thereof

Abstract

The invention provides a positive temperature coefficient polycrystalline silicon resistor structure and a manufacturing method thereof. The positive temperature coefficient polycrystalline silicon resistor structure comprises a plurality of polycrystalline silicon unit resistors which each comprise a nonmetallic polycrystalline silicon region and metallic polycrystalline silicon regions, whereineach nonmetallic polycrystalline silicon region is located in a middle region, a resistance value of each nonmetallic polycrystalline silicon region changes with a negative temperature coefficient, the metallic polycrystalline silicon regions are located at end regions, and resistance values of the metallic polycrystalline silicon regions change with a positive temperature coefficient. The adjacent polycrystalline silicon unit resistors are connected with metal wires with resistance values changing with a positive temperature coefficient through contact holes formed in the end regions. According to the manufacturing method, the ratio of the nonmetallic polycrystalline silicon regions relative to the metallic polycrystalline silicon regions is adjusted, and thus the positive changing amountof the resistance values of the metallic polycrystalline silicon regions along with temperatures is greater than or equal to the negative changing amount of the resistance values of the nonmetallic polycrystalline silicon regions along with temperatures. The positive temperature coefficient polycrystalline silicon resistor structure can avoid limitation of the performance of semiconductor devices, and high resistance values can be obtained under the conditions that process burden is not increased, device process stability is guaranteed and the area is not sacrificed.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a positive temperature coefficient polysilicon resistance structure and a manufacturing method thereof. Background technique [0002] Semiconductor resistance devices are one of the most widely used devices in semiconductor chip products, and the temperature characteristics of resistance are very important in product applications. Commonly used resistors are as follows. The resistance formed by using polysilicon material on the semiconductor substrate through the isolation of the oxide layer is called polysilicon (Poly) resistance. Please refer to Figure 14 , the relationship between the resistance of the diffusion region and the position of the polysilicon resistance is as follows. Taking the P-type silicon substrate as an example, it includes a P-type silicon substrate 301, an N-type diffused region resistor 302, an oxide layer 303, and a polysilicon resi...

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Problems solved by technology

In order to obtain a positive temperature coefficient resistance structure with a higher resistance value, it is generally obtained through the process of the above-mentioned diffusion region resistance or well region resistance. The disadvantage is that the accuracy or area is sacrificed. When the resistance accuracy requirements are very strict, the design is limited by the inability to obtain a polysilicon resistance structure with a positive temperature coefficient

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