^{1,a)}and F. Spaepen

^{1,b)}

### Abstract

The effect of changing the deposition rate on the development of stress in evaporated copper and silverthin filmsdeposited on oxidized silicon was examined. *In situ* stress measurements were made during deposition in ultrahigh vacuum using a scanning laser curvature system. In some experiments, the deposition rate was alternated without interruption of deposition. For copperthin films, a change in deposition rate has no effect on the development of the tensile stress, while the magnitude of the postcoalescence compressive stress decreases with increasing deposition rate. In silverfilms, the film thickness at the tensile maximum increases slightly with increasing deposition rate, while the magnitude of the postcoalescence compressive stress again decreases with increasing deposition rate. Analysis of the heat flow during deposition shows that the radiative heating and condensation contribute roughly equally to the temperature rise of the sample.

This work has been performed with the support of the Harvard MRSEC. One of the authors (A.L.D.) acknowledges support from a predoctoral NSF fellowship. The authors thank Professor John Weaver for his suggestion to consider the heat of condensation as a contributor to the temperature rise of the sample.

I. INTRODUCTION

II. EXPERIMENTAL TECHNIQUES

III. RESULTS

A. Tensile stress

B. Compressive stress

IV. DISCUSSION

A. Tensile stress

B. Compressive stress

V. CONCLUSIONS

### Key Topics

- Metallic thin films
- 63.0
- Thin films
- 56.0
- Copper
- 37.0
- Silver
- 30.0
- Thin film deposition
- 21.0

## Figures

Stress evolution as observed by the curvature of an elastic substrate, which is proportional to the product of the average stress and the film thickness .

Stress evolution as observed by the curvature of an elastic substrate, which is proportional to the product of the average stress and the film thickness .

(a) Film thickness at the tensile maximum vs deposition rate for copper thin films. (b) The average stress at the tensile maximum vs deposition rate for copper thin films.

(a) Film thickness at the tensile maximum vs deposition rate for copper thin films. (b) The average stress at the tensile maximum vs deposition rate for copper thin films.

(a) Film thickness at the tensile maximum vs deposition rate for silver thin films. (b) The average stress at the tensile maximum vs deposition rate for silver thin films.

(a) Film thickness at the tensile maximum vs deposition rate for silver thin films. (b) The average stress at the tensile maximum vs deposition rate for silver thin films.

(a) Incremental compressive stress at a thickness of in copper thin films deposited at a single deposition rate. The solid line is a linear fit with a slope of . (b) Incremental compressive stress at a thickness of in silver thin films deposited at a single deposition rate. The solid line is a linear fit with a slope of .

(a) Incremental compressive stress at a thickness of in copper thin films deposited at a single deposition rate. The solid line is a linear fit with a slope of . (b) Incremental compressive stress at a thickness of in silver thin films deposited at a single deposition rate. The solid line is a linear fit with a slope of .

(a) Alternating deposition of a copper thin film. (Top) The magnitude of the incremental compressive stress as a function of film thickness. (Bottom) as a function of film thickness. (b) Alternating deposition of a copper thin film. (Top) The magnitude of the incremental compressive stress as a function of film thickness. (Bottom) as a function of film thickness.

(a) Alternating deposition of a copper thin film. (Top) The magnitude of the incremental compressive stress as a function of film thickness. (Bottom) as a function of film thickness. (b) Alternating deposition of a copper thin film. (Top) The magnitude of the incremental compressive stress as a function of film thickness. (Bottom) as a function of film thickness.

Alternating deposition of a silver thin film. (Top) The magnitude of the incremental compressive stress as a function of film thickness. (Bottom) as a function of film thickness.

Alternating deposition of a silver thin film. (Top) The magnitude of the incremental compressive stress as a function of film thickness. (Bottom) as a function of film thickness.

(a) A log-log plot of in MPa at the tensile maximum vs film thickness in nm at the tensile maximum for copper thin films. The line is a linear fit with slope of . (b) A log-log plot of in MPa at the tensile maximum vs film thickness in nm at the tensile maximum for silver thin films. The line is a linear fit with slope of .

(a) A log-log plot of in MPa at the tensile maximum vs film thickness in nm at the tensile maximum for copper thin films. The line is a linear fit with slope of . (b) A log-log plot of in MPa at the tensile maximum vs film thickness in nm at the tensile maximum for silver thin films. The line is a linear fit with slope of .

Schematic diagram of the incoherent twin boundaries formed during deposition of a fcc metal. The growth sequence of the matrix is . Nucleation of the layer leads to formation of a twin, which continues to grow in the sequence . The gaps close up to form incoherent twin boundaries that contain partial dislocations. The resultant Burgers vectors of these dislocations correspond to tension in the growing film.

Schematic diagram of the incoherent twin boundaries formed during deposition of a fcc metal. The growth sequence of the matrix is . Nucleation of the layer leads to formation of a twin, which continues to grow in the sequence . The gaps close up to form incoherent twin boundaries that contain partial dislocations. The resultant Burgers vectors of these dislocations correspond to tension in the growing film.

Definition of and .

Definition of and .

## Tables

Change in the magnitude of the incremental compressive stress for the data shown in Fig. 5(a). The errors are those of the linear fit to the stress evolution data.

Change in the magnitude of the incremental compressive stress for the data shown in Fig. 5(a). The errors are those of the linear fit to the stress evolution data.

Change in the magnitude of the incremental compressive stress for the data shown in Fig. 5(b). The errors are those of the linear fit to the stress evolution data.

Change in the magnitude of the incremental compressive stress for the data shown in Fig. 5(b). The errors are those of the linear fit to the stress evolution data.

Change in the magnitude of the incremental compressive stress for the data shown in Fig. 6. The errors are those of the linear fit to the stress evolution data.

Change in the magnitude of the incremental compressive stress for the data shown in Fig. 6. The errors are those of the linear fit to the stress evolution data.

Material parameters for Cu and Ag for calculation of heat flux.

Material parameters for Cu and Ag for calculation of heat flux.

Material parameters for Si calculation of heat flux.

Material parameters for Si calculation of heat flux.

System parameters for calculation of the heat flux.

System parameters for calculation of the heat flux.

Estimates of heat flux onto the film using the parameters in Tables IV and VI.

Estimates of heat flux onto the film using the parameters in Tables IV and VI.

Article metrics loading...

Full text loading...

Commenting has been disabled for this content