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US 6,884,362 B2Granted
Mass production of cross-section TEM samples by focused ion beam deposition and anisotropic etching
AssigneeTexas Instruments Incorporated
InventorsLancy Tsung, Adolfo Anciso
Life of this patent
Estimating the term…
Abstract
A method of preparing a TEM sample. A focused ion beam is used to deposit a mask on the material to be sampled. Reactive ion etching removes material not protected by the mask, leaving a wall thin enough to be imaged by TEM.
Claims14
A method for making an integrated TEM sample holder with a sample, comprising:
- a. providing a semiconductor wafer having a top surface with a viewing site and a substantially parallel bottom surface;
- b. defining on the top surface of the semiconductor wafer an area of substantially rectangular shape containing the viewing site and dimensioned suitably for engaging a TEM double-tilt holder;
- c. depositing a metallic layer in the viewing-site area with a focused ion-beam means;
- d. shaping a base of the integrated TEM sample holder for engaging a TEM double-tilt holder including the steps of:
- i. mechanically severing from the semiconductor wafer a portion of semiconductor material having a first top surface containing the viewing site and a opposing bottom surface area corresponding to the rectangular-shaped area and four sidewalls substantially perpendicular to the top surface and the bottom surface, and;
- ii. mechanically removing a portion of semiconductor material downwardly from the first top surface to create a narrow center portion extending upwardly from the base of the sample holder, the center portion having two substantially parallel sidewalls substantially perpendicular to the bottom surface;
- and
- e. thinning a portion of the center-portion material with a reactive ion etching means downwardly from the top surface of the TEM holder adjacent to the metallic film to form the sample.
5 more elements
The method of making an integrated TEM sample holder with a sample;
- comprising the steps of:
- a. providing a semiconductor wafer having a top surface with a viewing site and a substantially parallel bottom surface;
- b. forming a base of the sample holder suitable for engaging a TEM double-tilt holder including the steps of:
- i. removing a slab of the wafer containing a top area containing the viewing site and a portion of the bottom surface suitably dimensioned for engaging a TEM double-tilt holder;
- and
- ii. removing a portion of the semiconductor material downwardly from the top surface of the slab to form a narrow center portion containing the view site;
- and
- c. thinning the center portion to form the sample.
5 more elements
The method of 6, further comprising the step of depositing an oxide film on the top surface of the semiconductor wafer, covering the viewing site.
Dependencies are inferred from the claim text.