Abstract:
A technique (500) for manufacturing a micro-electro-mechanical (MEM) structure includes a number of steps. Initially, a substrate is provided (502). Next, a plurality of trenches are etched into the substrate with a first etch (508). Then, a charging layer is formed at a bottom of each of the trenches to form undercut trenches (510). Finally, a second etch is provided into the undercut trenches. The charging layer causes the second etch to laterally etch foots in the substrate between the undercut trenches (512). The footers undercut the substrate to release a portion of the substrate for providing a movable structure between the undercut trenches and above the footers.
Abstract:
An MEMS-based method for manufacturing a sensor comprises the steps of: forming a shallow channel (120) and a support beam (140) on a front surface of a substrate (100); forming a first epitaxial layer (200) on the front surface of the substrate (100) to seal the shallow channel (120); forming a suspended mesh structure (160) below the first epitaxial layer (200); and forming a deep channel (180) at a position on a back surface of the substrate (100) corresponding to the shallow channel (120), so that the shallow channel (120) is in communication with the deep channel (180). In the Method of manufacturing a MEMS-based sensor, when a shallow channel is formed on a front surface, a support beam of a mass block is formed, so the etching of a channel is easier to control, the process is more precise, and the uniformity and the homogeneity of the formed support beam are better.
Abstract:
The invention relates to a method for the anisotropic etching of structures on a semiconductor body, in particular for etching recesses in a silicon body (18) which are defined laterally in a precise manner by an etching mask, using a plasma (28). An ion-accelerator voltage is applied to the semiconductor, at least during an etching step which continues for a predetermined period. Said ion-accelerator voltage is induced, in particular, by a high-frequency alternating current. The duration of the etching step is subdivided further into at least two etching periods, between which the applied ion-accelerator voltage is modified. A preferred embodiment contains two etching periods, whereby a higher accelerator voltage is used during the first etching period than during the second etching period. The duration of the first etching period can also be determined dynamically or statically during the etching steps using a device for detecting a polymer breakthrough. In addition, high frequency pulses or pulse packets with an adjustable pulse-pause ratio are preferably used to generate and adjust the level of the accelerator voltage.
Abstract:
A MEMS comprising a sacrificial structure, which comprises a faster etching portion and a slower etching portion, exhibits reduced damage to structural features when in forming a cavity in the MEMS by etching away the sacrificial structure. The differential etching rates mechanically decouple structural layers, thereby reducing stresses in the device during the etching process. Methods and systems are also provided.