Manufacture method for insulated gate bipolar transistor (IGBT) device

Abstract

The invention discloses a manufacture method for an insulated gate bipolar transistor (IGBT) device. Before a metal layer of an IGBT separation device deposits, a film with positive stress is formed at the back of a silicone wafer of a formed device structure. The manufacture method can effectively offset stress of the metal layer, improves warping degree of the silicon wafer and enables follow-up photoetching and etching on the metal layer to be constructed normally.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits, in particular to a method for manufacturing a low-stress IGBT (insulated gate bipolar transistor) device. Background technique [0002] In various semiconductor device structures, trench thyristors are widely used in various power devices due to their special channel characteristics and electrical characteristics. Especially for IGBT devices, due to its unique high-voltage and high-current working environment, its trench IGBT devices require larger-sized trench gates. With the improvement of device performance requirements by end customers, the trench required by the device is getting deeper and deeper, and the stress of the trench gate is becoming more and more prominent. [0003] The radius of curvature of each step in the manufacturing process of IGBT devices is shown in Table 1. [0004] Process steps Wafer radius of curvature (m) Shot 332 tr...

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Problems solved by technology

However, since the IGBT separation device requires a very thick metal layer, when the production of the IGBT separation device enters the final metal layer deposition, the backside process is not performed before the final metal layer is deposited. After the final metal layer is deposited, the thick metal layer will produce very Due to the large normal stress, no matter how the previous process steps improve the radius of curvature after trench gate deposition, the stress deterioration of the thick metal layer cannot be overcome. Severe stress will lead to an increase in the warpage of the silicon wafer, making subsequent metal layer photolithography Difficulties in handling with the etching process, which may even lead to failure of silicon wafer tape-out or occurrence of debris events (see figure 1 shown)

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