Gap-filling property of Cu film by chemical vapor deposition

Abstract

Correlation between the early stage of copper metal organic chemical vapor deposition and the material properties of thin filmThe gap-filling property of Cu deposited by chemical vapor deposition was investigated in 1/4-m-wide trenches and 1/4-m-diam holes. Attention was paid to the influences on the gap-filling property of both substrate temperature and partial pressure of the source gas. At a low deposition temperature of 180°C, Cu could completely fill a hole with an aspect ratio of 7. A high deposition rate could be obtained at the high substrate temperature and high partial pressure of the source gas. However the coverage probably deteriorated because of the increase in sticking coefficient due to an increase in the reaction rate at high temperature. As the source gas pressure increased, the deposition rate increased and saturated in the high source pressure region. The good gap-filling property at high source pressures was attributed to the Langmuir-Hinshelwood reaction where almost the same deposition rate is realized from the top to the bottom of the trench. At a high temperature of 215°C, voids were observed at both the center and along the wall of the trench. The voids along the wall were assumed to be formed at the initial stage of deposition. They disappeared with an increase in source gas flow rate. Therefore, the formation of voids could be due to an insufficient supply of source gas. By annealing the Cu film, its properties of increase in grain size and the reduction in the amount of C, O, and F contaminants were improved. After annealing and chemical mechanical polishing treatment, scanning electron microscopy observation showed Cu interconnecting lines with grains larger than the wire width.

Low-Temperature Deposition of Conformal Copper Films in Supercritical CO2by Catalytic Hydrogen Reduction of Copper Hexafluoroacetylacetonate

“…A current method widely used for copper deposition is electroplating, which requires a copper seed layer (work as a cathode) formed with physical vapor deposition. Also, various kinds of chemical vapor deposition (CVD) techniques have been studied for conformal copper deposition over the past decade in order to replace the electroplating with the CVD, which is favorably used in the semiconductor industry. − Although the recent CVD techniques enable us to make a conformal copper film at a rapid growth rate and fill small features with no voids and seams, − adhesions of copper films on barrier layers such as TiN, TaN, and Ta are poor in most of the techniques . High deposition temperature (>200 °C) is another drawback of this technique.…”

Metalorganic Chemical Vapor Deposition of Copper Using (Hexafluoroacetylacetonate)Cu(I)(3,3-dimethyl-1-butene) with a Liquid Delivery System

“…This result is similar to the previous results. 17,18) Burke et al 18) reported that the conformality was directly proportional to the precursor flow rate. This is because the increase in precursor flow leads to a higher probability of adsorption/ re-emission within the via or trench structure.…”

“…The enhancement of precursor concentration can be achieved by increasing the precursor partial pressure in the reaction zone by the increase of the precursor flow while keeping all other process parameters fixed. The partial pressure of precursor (P precursor ) is defined as follows: 17,18) …”

Enhancement of Interconnectivity in the Channels of Pentacene Thin‐Film Transistors and Its Effect on Field‐Effect Mobility

“…[12][13][14] Furthermore, in several crystallographic and morphological studies, attempts have been made to correlate the transport properties of pentacene thin films with morphology and molecular orientation. [15,16] However, although the voids that act as traps or barriers to hopping transport at the interface between the active layer and the insulator substrate are usually formed during the pentacene deposition process, [17] little is known about the relationship between the voids at the interface and carrier transport. [9] Here, we report the effect of voids at the interface between the pentacene film and the dielectric layer on the performance of pentacene transistors, and suggest a methodology for filling such voids and improving the interconnectivity in the channels of pentacene thin films by controlling the pentacene sublimation rate.…”