Near field acoustic ultrasonic microscope system and method

A method of performing acoustic microscopy, the steps of the method comprising:

• positioning, over a target object, a cantilever arm having an upper surface and a lower surface, said cantilever arm having a sharp tip on its lower surface and a piezoelectric thin film on at least a portion of its upper surface;
• applying to said piezelectric thin film an excitation signal having a frequency of at least 50 Megahertz so as to generate high frequency acoustic signals which are transmitted through said sharp tip;
• and
• receiving said high frequency acoustic signals after said high frequency acoustic signals have interacted with a target object.

A method of performing acoustic microscopy, the steps of the method comprising:

• positioning, over a target object, a probe having an upper surface and a lower surface, said probe having a sharp tip on its lower surface and a piezoelectric thin film on at least a portion of its upper surface;
• said probe being positioned with respect to said target object so as to leave a gap between said sharp tip and said target object;
• generating an RF electrical field in said gap between said sharp tip and said target object;
• receiving via said piezoelectric thin film RF acoustic signals caused by said RF electrical field in said gap;
• and
• measuring characteristics of said target object by measuring said received RF acoustic signals.

A method of performing acoustic microscopy, the steps of the method comprising:

• attaching a piezoelectric thin film to a target object;
• positioning, over said target object, a probe having a sharp tip on its lower surface;
• said probe being positioned with respect to said target object so as to leave a gap between said sharp tip and said target object;
• generating an RF electrical field in said gap between said sharp tip and said target object;
• receiving via said piezoelectric thin film RF acoustic signals caused by said RF electrical field in said gap;
• and
• measuring characteristics of said target object by measuring said received RF acoustic signals.

An acoustic microscope assembly, comprising:

• a probe having an upper surface and a lower surface;
• a sharp tip on the lower surface of said probe;
• a piezoelectric thin film on at least a portion of the upper surface of said probe;
• high frequency excitation means, coupled to said piezoelectric thin film, for applying an excitation signal having a frequency of at least 50 Megahertz to said piezoelectric thin film so as to generate high frequency acoustic signals;
• wherein said high frequency acoustic signals are transmitted through said sharp tip;
• acoustic signal receiving means for receiving said high frequency acoustic signals after said high frequency acoustic signals have interacted with a target object;
• positioning means for positioning said sharp tip with respect to said target object;
• and
• control means, coupled to said high frequency excitation means, said acoustic signal receiving means and said positioning means, for moving said sharp tip so as to scan said target object, and for measuring characteristics of said target object at various positions thereof by varying the frequency of said high frequency excitation signal while monitoring said acoustic signals received by said acoustic signal receiving means so as to measure resonant frequency of said transmitted high frequency acoustic signals.

An acoustic microscope assembly comprising:

• a probe having an upper surface and a lower surface;
• a sharp tip on the lower surface of said probe;
• a piezoelectric thin film on at least a portion of the upper surface of said probe;
• high frequency excitation means, coupled to said piezoelectric thin film, for applying an excitation signal having a frequency of at least 50 Megahertz to said piezoelectric thin film so as to generate high frequency acoustic signals;
• said high frequency excitation means applying a continuous wave signal to said piezoelectric thin film so as to generate a continuous wave high frequency acoustic signal;
• wherein said high frequency acoustic signals are transmitted through said sharp tip;
• acoustic signal receiving means for receiving said high frequency acoustic signals after said high frequency acoustic signals have interacted with a target object;
• positioning means for positioning said sharp tip with respect to said target object;
• and
• control means, coupled to said high frequency excitation means, said acoustic signal receiving means and said positioning means, for moving said sharp tip so as to scan said target object, and for measuring characteristics of said target object at various positions thereof by varying the frequency of said high frequency excitation signal while monitoring said acoustic signals received by said acoustic signal receiving means so as to measure resonant frequency of said transmitted high frequency acoustic signals.

A method of performing acoustic microscopy, the steps of the method comprising:

• positioning, over a target object, a probe having an upper surface and a lower surface, said probe having a sharp tip on its lower surface and a piezoelectric thin film on at least a portion of its upper surface;
• applying to said piezoelectric thin film on excitation signal having a frequency of at least 50 Megahertz so as to generate high frequency acoustic signals which are transmitted through said sharp tip;
• moving said sharp tip so as to scan said target object;
• measuring characteristics of said target object at various positions thereof by varying the frequency of said high frequency excitation signal while monitoring said acoustic signals received by said acoustic signal receiving means so as to measure resonant frequency of said transmitted high frequency acoustic signals;
• and
• receiving said high frequency acoustic signals after said high frequency acoustic signals have interacted with a target object.