A kind of preparation technology of welding pad structure

Abstract

The invention provides a preparation process of a welding pad structure. An organic polymer with high dielectric constant and excellent channel filling performance is adopted to replace a silicon oxide passivating layer in the prior art to complete channel filling and covering after a welding pad metal layer is etched, so as to protect the welding pad metal layer from being damaged by a subsequentprocess; deposition of an oxide passivation layer is omitted, and a titanium nitride light absorption layer on the top layer is removed after the welding pad metal layer is etched; in addition, in the subsequent welding pad metal layer surface exposing step, plasma dry etching is not needed to remove the oxide and the top layer titanium nitride; and therefore, subsequent alloying treatment is notneeded to eliminate PI layer charge accumulation caused by the plasma dry etching, so that the post-section preparation period is shortened, and production cost is greatly lowered.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a process method of a back-end process, in particular to a process for preparing a pad structure. Background technique [0002] With the rapid development of microelectronics technology, the size of CMOS (Complementary Metal Oxide Semiconductor) devices is also decreasing day by day. The current mainstream semiconductor process size has reached the order of 90nm and 65nm, and correspondingly, new requirements are constantly being put forward for the process technology. [0003] Among them, in the back-end process (Back-End-Of-Line, BEOL) of the semiconductor manufacturing process, after the top metal (Top Metal) wiring layer is fabricated, an inter-metal dielectric layer needs to be fabricated on the top metal wiring layer And the metal pad, the inter-metal dielectric layer is usually silicon oxide, and the metal pad is usually an aluminum pad (Al PAD), the metal pad b...

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Problems solved by technology

[0014] However, in the preparation process of the above pad structure, there are the following problems: first, the deposition of the passivation layer and the PI layer will greatly increase the cost of the back-end process, and will greatly prolong the manufacturing cycle of the back-end process; Second, it is precisely because of the existence of the passivation layer and the light-absorbing layer (such as TiN) that it is necessary to etch after the PI layer is baked and solidified to expose the surface of the pad metal layer 3, and this aspect will undoubtedly prolong the process. The entire process cycle, on the other hand, the plasma dry etching (Dry Etch) of the passivation layer can also easily lead to the accumulation of charges in the PI layer, which in turn leads to the need for subsequent additional alloying treatments to eliminate these unnecessary charges to avoid degradation. The performance of semiconductor products

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