Semiconductor substrate batch demounting apparatus

#This invention relates generally to semiconductor devices, and more specifically, to apparatuses for manufacturing semiconductor devices.

#The demounting or debonding process for separating thinned semiconductor substrates from their support substrates is one of the main identified causes for semiconductor substrate breakage during the manufacturing of semiconductor devices. Semiconductor substrate breakage is very costly because the demounting step is performed near the end of the manufacturing process, after most of the manufacturing costs have already been incurred.

#Currently, the majority of the semiconductor device manufacturing industry uses a single semiconductor substrate separation process for semiconductor substrate demounting. Using this method, a single semiconductor substrate is separated from its support substrate one at a time. This process typically involves: (1) placing the support substrate and the semiconductor substrate, or ceramic substrate, onto a heated surface to melt an adhesive or grip material such as a wax or a mixture of wax with photoresistor that connects the support substrate to the semiconductor substrate, and (2) manually demounting the semiconductor substrate from the support substrate after the adhesive is melted in order to separate the semiconductor substrate from the support substrate.

#The following describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other possible embodiments as well as the ones specifically described. For a definition of the complete scope of the invention, the reader is directed to the appended claims.

#This invention allows a highly efficient, high capacity batch demounting process for separating thinned semiconductor substrates from support substrates in contrast to the existing single semiconductor substrate separation process. This invention involves vertically aligning a standard Teflon™ (a trade name for Du Pont's polytetraflueroethylene fiber) cassette on the bottom (bottom cassette) with a modified metal cassette (top cassette) on the top. The purpose of the top cassette is to allow only the thinned semiconductor substrates to slide down and to block the support substrates from passing through to the bottom cassette. The semiconductor substrates and the coupled support substrates that are coupled by an adhesive are loaded into a row of slots in the top cassette. The top cassette is configured to accept the semiconductor substrate whereby a surface of the semiconductor substrate is positioned approximately parallel to a force of gravity when inserted. The two cassettes can be placed in a basket made of a metal frame and net sidewalls. The two cassettes and the substrates, which may optionally be contained in the basket, are introduced to a dissolving agent such as a hot chemical (gas, vapor, or liquid) or heat alone to dissolve or melt the adhesive and thus to weaken the cohesive force between the semiconductor substrates and the support substrates. Then the semiconductor substrates will be gradually pulled down from the support substrates by gravitational force and will vertically slide down into the bottom cassette. When a liquid chemical solvent is used as a dissolving agent, the liquid chemical solvent works as a buffer to allow the semiconductor substrates to gently drop into the bottom cassette and thus to avoid the semiconductor substrate from fracturing by reducing their rate of descent.

#The bottom cassette can be made of a material containing Teflon™ if the solvent temperature is lower than about 150° C. Otherwise, if the solvent temperature is higher than 150° C., it can be a standard metal cassette with Teflon™ coating on the inside to prevent the semiconductor substrates from being scratched or otherwise damaged by the metal and to withstand high temperature.