Apparatus and method of temperature conrol during cleaving processes of thick film materials

Abstract

An apparatus for temperature control of manufacture of thick film materials includes a stage comprising a planar surface for supporting a bulk material to be implanted and subsequently cleaved. The bulk material has a surface region, a side region, and a bottom region which provides a volume of material and defines a length between the bottom region and the surface region. The apparatus further includes a mechanical clamp device adapted to engage the bottom region to the planar surface of the stage such that the bulk material is in physical contact with the planar surface for thermal energy to transfer through an interface region between the bulk material and the stage while the surface region is substantially exposed. Additionally, the apparatus includes a sensor device configured to measure a temperature value of the surface region and generate an input data. The apparatus further includes an implant device configured to perform implantation of a plurality of particles through one or more portions of the surface region of the bulk material and a controller configured to receive and process the input data to increase and / or decrease the temperature value of the surface region through at least the interface region between the planar surface of the stage and the bottom region of the bulk material.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The instant nonprovisional patent application claims priority to U.S. Provisional Patent Application No. 60 / 886,912, filed Jan. 26, 2007, and which is incorporated by reference in its entirety herein for all purposes.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to techniques including methods and apparatuses for manufacturing materials. More particularly, the present methods and apparatuses include a temperature control for cleaving free-standing thick films from material in bulk form, such as a silicon ingot. Such free-standing thick films are useful as a photovoltaic material such as a solar cell. But, it will be recognized that embodiments in accordance with the present invention have a wider range of applicability; it can also be applied to other types of applications such as for three-dimensional packaging of integrated semiconductor devices, photonic devices, piezoelectronic devices, flat panel displays, m...

AI Technical Summary

Benefits of technology

[0008]A free-standing thick film of semiconductor material having a thickness of 15 μm or greater, may be cleaved from a bulk material utilizing implantation of an ionic species at a desired surface temperature. In an embodiment, the cleaving involves removably holding the bulk material through a seal on a temperature controlled stage using a mechanical clamp device, then implanting particles such as ions at a first, lower temperature to create a cleave region, and then implanting particles such as ions at a second, higher temperature to enhance stress in the cleave region. In another embodiment, the seal between the temperature controlled stage and the bottom of the bulk material creates a thin cavity capable of filling a gas with adjustable pressure. In yet another embodiment, by adjusting the gas pressure in the thin cavity the heat transfer from the surface to bottom of the bulk material and further the surface temperature for implanting are controlled. In certain embodiments, the bottom of the bulk material is glued (e.g. using thermally conductive glue or thermally conductive epoxies) to a thermal and mechanical adapter plate which can facilitate the mounting and handling of the bulk material. Depending upon the particular embodiment, the adapter plate can be slightly larger than, smaller than, or the same size in cross section as, the bulk material. In accordance with certain embodiments, the adapter plate can be reused on other bulk substrates. The resulting cleaved free-standing thick films of semiconductor material such as single crystal silicon, are particularly suited for use in the collection of solar energy.

[0010]In another specific embodiment, the invention provides an apparatus of mounting a bulk material for manufacture of one or more thick films. The apparatus includes a stage comprising a planar surface for supporting the bulk material. The bulk material includes a planarized surface region, a planarized end region, and a side region having a length from the surface region to the end region. The apparatus further includes a mechanical clamp device adapted to engage the planarized end region of the bulk material with the planar surface of the stage such that the surface region and at least 70% length of the side region from the surface region is substantially exposed and can be cleaved for manufacture of one or more thick films without interference of the clamp device.

[0014]According to certain embodiments, the bottom region of the bulk material opposite to the surface region, can be contacted thermally and mechanically through an adapter or interface plate. The bulk material could be secured to such an adapter plate using glue or other techniques, with an opposing face of the plate mounted onto the temperature controlled stage. Particular embodiments of the adapter plate can also allow for clamp mounting. In such an embodiment, the adapter plate with clamp mounting eliminates the requirement to clamp the bulk material directly, and improves utilization of the bulk material by allowing the bulk material to be cleaved closer to the bottom region.

[0015]Use of an adapter plate according to embodiments of the present invention could also desirably relax the planarization tolerances of the bulk material bottom region and thus reduce costs. For example, under certain conditions the bottom of the ingot can be slightly uneven. However, this unevenness can be offset by the attachment between the adapter and susceptor. In particular, the adapter can have pins or seats to help align the ingot to it.

Problems solved by technology

Unfortunately, such petroleum sources have become depleted and have lead to other problems.

Although effective, these solar cells still have many limitations.

These materials are often difficult to manufacture.

While these polysilicon plates may be formed in a cost effective manner, they do not exhibit the highest possible efficiency in capturing solar energy and converting the captured solar energy into usable electrical power.

Such single crystal silicon is, however, expensive to manufacture and difficult to use for solar applications in an efficient and cost effective manner.

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