High temperature subatmospheric chemical vapor deposited undoped silicate glass - A solution for next generation shallow trench isolation

Undoped silicate glass deposited using the tetraethylorthosilicate (TEOS) a nd ozone thermal reaction has been selected as one of the candidates for sh allow trench isolation applications. As a replacement for existing low pres sure or atmospheric pressure chemical vapor deposition processes for device dimensions below 0.25 mu m, TEOS/ozone films deposited at high temperature (>550 degrees C) exhibit the superior qualities in terms of void-free tren ch fill. In this paper, we present some characterization of the silicon oxi de film deposited in the subatmospheric pressure regime using TEOS/ozone ch emistry, aimed at developing a high-quality dielectric film to meet shallow trench isolation gap-fill requirements. It is also identified that low ozo ne/TEOS ratio reduces surface and pattern sensitivity. Therefore, no additi onal treatment or predeposition is necessary. Moreover, to enhance the etch resistance of the silicon oxide, the as-deposited film is annealed at high temperature for densification and bond reconstruction. (C) 1999 The Electr ochemical Society. S0013-4651(98)03-029-8. All rights reserved.