Multi-layer composite passivation layer structure of bipolar circuit and its production process

Abstract

The present invention provides the multilayer composite passivation film structure of the Bipolar circuit, comprising the underlying silicon oxide film layer deposited on the surface of the silicon substrate and the silicon nitride film layer deposited on the silicon oxide film layer, the silicon oxide film layer A certain proportion of phosphine is doped in the layer, and the silicon oxide film layer is an undoped silicon dioxide layer, a doped phosphosilicate glass layer, and an undoped silicon dioxide layer in sequence. Simultaneously, the present invention also provides the multilayer composite passivation film production method of Bipolar circuit, utilizes the multilayer composite passivation film structure of Bipolar circuit realized by the present invention to have anti-scratch, anti-moisture, high density, low film stress, Higher gettering ability, better step coverage ability, excellent photoelectric performance, electrical characteristics and thermal stability, reducing soft breakdown and solving problems such as poor reliability.

Description

technical field [0001] The invention relates to a passivation layer structure and a passivation layer generation process in the field of semiconductor manufacturing, in particular to a multilayer composite passivation layer structure of a Bipolar circuit and a generation process method thereof. Background technique [0002] Silicon oxide is widely used as a conventional passivation film structure in BiDolar circuits due to its relatively small stress on the silicon substrate and aluminum film. However, due to the shortcomings of silicon oxide such as radiation sensitivity, low scratch resistance, poor photoelectric performance, weak moisture resistance and mobile ion penetration, it is limited in special semiconductor processes and devices (such as silicon photoelectric application in conversion circuits, etc.). For the silicon oxide film formed by the conventional low-pressure chemical vapor deposition method, due to its better step conformality, in the double-layer wiring...

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Problems solved by technology

However, due to the shortcomings of silicon oxide such as radiation sensitivity, low scratch resistance, poor photoelectric performance, weak moisture resistance and mobile ion penetration, it is limited in special semiconductor processes and devices (such as silicon photoelectric conversion circuits, etc.)

For the silicon oxide film formed by the conventional low-pressure chemical vapor deposition method, due to its better step conformality, in the double-layer wiring process without planarization process, the passivation film is between the vertical edge and the surface parallel to the layer. Gaps are prone to appear at the corners of high steps, which weakens the protective effect of the silicon oxide passivation film here, thereby affecting the thermal stability and reliability of the circuit

Silicon nitride is another commonly used passivation layer dielectric material. Its barrier effect on mobile ions and water vapor is the best among all commonly used dielectric materials, and it has high scratch resistance. However, silicon nitride material The step coverage ability of the aluminum alloy is poor, and it is prone to breakage at high steps without a planarization process. At the same time, its expansion coefficient is greatly different from that of aluminum materials, and it is easy to deform after high temperature annealing

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