Methods for improving quality of high temperature oxide (HTO) formed from halogen-containing precursor and products thereof and apparatus therefor
View Patent ↗A method and apparatus are disclosed for reducing the concentration of chlorine and/or other bound contaminants within a semiconductor oxide composition that is formed by chemical vapor deposition (CVD) using a semiconductor-element-providing reactant such as dichlorosilane (DCS) and an oxygen-providing reactant such as N 2 O. In one embodiment, a DCS-HTO film is annealed by heating N 2 O gas to a temperature in the range of about 825° C. to about 950° C. so as to trigger exothermic decomposition of the N 2 O gas and flowing the heated gas across the DCS-HTO film so that disassociated atomic oxygen radicals within the heated N 2 O gas can transfer disassociating energy to chlorine atoms bound within the DCS-HTO film and so that the atomic oxygen radicals can fill oxygen vacancies within the semiconductor-oxide matrix of DCS-HTO film. An improved ONO structure may be formed with the annealed DCS-HTO film for use in floating gate or other memory applications.
1. An improved High Temperature Oxidation (HTO) film formed from dichlorosilane (DCS), disposed in a monolithic integrated circuit and characterized by:
a chlorine concentration of less than 4000 10 10 atoms/cm 2 essentially throughout the film.
2. The improved DCS-HTO film of claim 1 and further characterized by:
a chlorine concentration of less than about 400 10 10 atoms/cm 2 essentially throughout the film.
3. The improved DCS-HTO film of claim 2 and further characterized by:
a chlorine concentration of less than about 165 10 10 atoms/cm 2 essentially throughout the film.
4. The improved DCS-HTO film of claim 2 and further characterized by:
a sulfur concentration of less than about 240 10 10 atoms/cm 2 essentially throughout the film.
5. The improved DCS-HTO film of claim 2 and further characterized by:
an iron (Fe) concentration of less than about 0.4 10 10 atoms/cm 2 essentially throughout the film.
6. The improved DCS-HTO film of claim 2 and further characterized by:
an iodine (I) concentration of less than about 1.3 10 10 atoms/cm 2 essentially throughout the film.
7. The improved DCS-HTO film of claim 1 and further characterized by:
said film defining an insulative separation between a floating gate of said integrated circuit and a control gate of the integrated circuit.
8. A monolithic integrated circuit comprising:
(a) a first polycrystalline semiconductor electrode; and
(b) a first annealed DCS-HTO film disposed on a surface of the first polycrystalline semiconductor electrode, where said first annealed DCS-HTO film is characterized by a chlorine concentration of less than about 400 10 10 atoms/cm 2 essentially throughout the first annealed DCS-HTO film.
9. The monolithic integrated circuit of claim 8 and further comprising:
(c) a nitride film disposed on a surface of the first annealed DCS-HTO film; and
(d) a second annealed DCS-HTO film disposed on a surface of the nitride film, where said second annealed DCS-HTO film is characterized by a chlorine concentration of less than about 400 10 10 atoms/cm 2 essentially throughout the second annealed DCS-HTO film.
10. The monolithic integrated circuit of claim 9 and further comprising:
(e) a second polycrystalline semiconductor electrode disposed on a surface of at least one of said first and second annealed DCS-HTO films.
11. The monolithic integrated circuit of claim 10 and further comprising:
(f) a thermally-grown oxide extending from said second polycrystalline semiconductor electrode.
12. The monolithic integrated circuit of claim 8 and further comprising:
(c) a monocrystalline substrate in contact with at least a portion of said first annealed DCS-HTO film.