Oxide deposition method of shallow groove isolation region

Abstract

An oxide deposition method of shallow groove isolation area comprises that: a groove is formed on a semiconductor substrate; a sidewall oxide layer is formed on the sidewall and the bottom of the groove; a first oxide layer is deposited on the sidewall oxide layer by low temperature process; the first oxide layer is etched to enlarge a second deposition opening; a second oxide layer is deposited on the first oxide layer. HDPCVD is applied to perform the deposition-etching-deposition technique and can achieve the oxide deposition in the shallow groove isolation area / film layer with no holes; through controlling the temperature of deposition reaction, the density of the deposited film layer can be reduced and further the shallow groove isolation area / film layer oxides with low stress can be achieved.

Description

technical field [0001] The invention relates to the technical field of integrated circuit manufacturing, in particular to an oxide deposition method for shallow trench isolation regions. Background technique [0002] As the integration level of integrated circuits increases, the size of isolation regions between active regions in semiconductor devices must continue to shrink. The traditional area oxidation method (LOCOS) used to isolate the active region has a bird's beak shape at the edge of the field oxide layer due to the oxidation at the edge of the active region, so that between the active regions in the semiconductor device Effective isolation length is limited. Since the above-mentioned disadvantages of the region oxidation method can be avoided, the shallow trench isolation (Shallow Trench Isolation, STI) process has been widely used in isolation between active regions in semiconductor devices in recent years. [0003] In order to ensure the filling effect of STI, ...

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Problems solved by technology

[0008] Obviously, although this method provides a method to reduce the stress and erosion of the sidewall oxide layer of shallow trench isolation, it still cannot solve the gap filling problem.

At the same time, the simple combination of the method and the above-mentioned technical solution that can solve the gap filling problem, that is, after the high-density plasma chemical vapor deposition of multiple deposition steps, and then perform an on-site steam generation process, theoretically, can provide both guaranteed An STI / film oxide deposition method with high deposition quality and reduced film stress, but it needs to add a separate process step, which complicates the process

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