Semiconductor chip

Details Semiconductor chip Semiconductor chip

1997-10-10

2000-02-01

Jones, Deborah

Stock material or miscellaneous articles

Structurally defined web or sheet

Discontinuous or differential coating, impregnation or bond

428209, 257709, 257711, 174 74R, B32B 300, H01L 2312

Patent

active

060200502

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention is directed to a semiconductor chip with a membrane resting on metallic supports.
2. Description of the Related Art
Particularly in the manufacture of sensors and actuators, it is often required in semiconductor technology to produce a layer-like structure free above a substrate. Such a structure can be utilized, for example, as a membrane for pressure sensors, as a closure layer of a cavity or as an upper cooperating electrode for capacitative sensors or actuators. A thin aluminum layer, for example, as applied in the course of a CMOS process as a metallization level can be employed for such a membrane. Such a metal layer yields an electrically conductive membrane that, after the removal of the material situated thereunder, can serve, for example, as a cooperating electrode or as a pressure membrane for capacitative measurement. As a result of the mechanical stability, such a metal layer can also be advantageously employed when a cavity, in which a micromechanical elements moves, is to be covered toward the outside, such as, for example, given the component disclosed in German Patent Application P 19509868. A high, thermally caused tensile stress that deteriorates the mechanical stability of a membrane layer that is not supported surface-wide usually occurs in the metallization.


SUMMARY OF THE INVENTION

An object of the present invention is to provide a semiconductor chip, whereby a membrane-like structure is realized with adequate mechanical stability.
This and other objects and advantages are achieved with the semiconductor chip having a membrane resting on supports, the membrane having a surface at the side provided with the supports, the surface being free of solid material other than the supports. The supports each have an end opposite the membrane, the end being anchored in a respective opening in a solid material. The openings have an outside edge that corresponds to the lateral dimensions of the support.
Further developments provide that the membrane is a metal layer. The membrane may include recesses, holes or windows in it.
In a preferred embodiment, the supports have a part anchored in the solid material, the part having a laterally limiting outside surface in the plane defined by the membrane and at least one section extending perpendicular to the plane of the membrane. The support part anchored in the solid material is a cuboid in one embodiment, while in another it is cylindrically shaped.
An example of the membrane according to the invention is rectangular in shape and the supports are in the form of two webs at the edges of the membrane opposite one another. The supports may be anchored in the solid material to a depth of 0.5 to 5 .mu.m, and preferably to a depth of 1.5 .mu.m. The solid material in which the supports are anchored is preferably semiconductor material.
The underlying idea of the invention is comprised in securing the membrane layer on pillar-like or web-like supports and anchoring these supports in solid material to a certain depth such that the supports are firmly held on the foundation even given the occurrence of distortions in the membrane layer. The supports that hold the membrane at a spacing from the substrate are located between the membrane and a substrate, which is a semiconductor structure or the like, so that a free surface of the membrane layer can be present at that side of the membrane facing toward the substrate or the semiconductor layer structure. This free surface can be formed, for example, by a cavity produced between the substrate and the membrane. It is also possible that the membrane layer is carried only by supports which extend entirely outside of the remaining semiconductor material. In this case, the membrane is completely free of further solid material, at least at the side of the membrane facing toward the substrate. It is critical that the pillar-like or web-like supports carrying the membrane layer have their ends lying opposite the membrane anchored up to a certai

REFERENCES:
patent: 4256382 (1981-03-01), Piliavin et al.
patent: 5760455 (1998-06-01), Hierold et al.

Affiliated with

Also associated with

Rating

Semiconductor chip does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Semiconductor chip, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor chip will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-935649