FIELD

Embodiments of the present disclosure generally relate to an apparatus for processing substrates. More particularly, the disclosure relates to apparatus and methods for heating and cooling wafers for batch processing.

BACKGROUND

The process of forming semiconductor devices is commonly conducted in substrate processing platforms containing multiple chambers. In some instances, the purpose of a multi-chamber processing platform or cluster tool is to perform two or more processes on a substrate sequentially in a controlled environment. In other instances, however, a multiple chamber processing platform may only perform a single processing step on substrates; the additional chambers are intended to maximize the rate at which substrates are processed by the platform. In the latter case, the process performed on substrates is typically a batch process, wherein a relatively large number of substrates, e.g. 25 or 50, are processed in a given chamber simultaneously. Batch processing is especially beneficial for processes that are too time-consuming to be performed on individual substrates in an economically viable manner, such as for ALD processes and some chemical vapor deposition (CVD) processes.

The ALD platform has a wide range of applications with various requirements and constraints that demands a flexible architecture. Platform requirements include wafer preheating, post cooling, preheat & post cool, throughput from 30 wph (wafers per hour) to 270 wph, high vacuum loadlocks, and numerous other specifications can be a challenge to provide the functionality with low entitlement cost.

ALD batch processing platforms provides standard and active wafer cooling capable loadlocks. The high temperature processes (>450° C.) benefit from wafer preheating prior to being placed on the process chamber susceptor. Currently, room temperature wafers are preheated in the process chamber for as long as 3 minutes. This costs valuable processing time and significantly reduce system throughput for shorter processes.

Current ALD processors have numerous methods to heat and cool single wafers in a loadlock. However, the ALD batch processing platforms can process batches with six wafers or more. Single wafer loadlock cycles are too slow (36 seconds) to the meet the 15 second exchange budget. Therefore, there is a need in the art for apparatus and methods for preheating and post-cooling batches of wafers for batch processing.

SUMMARY

One or more embodiments of the disclosure are directed to wafer cassettes comprising a wall supporting a plurality of cold plates. The wall allows access to a front side of at least some of the cold plates. A plurality of LED lamps are positioned against a back side of the cold plates and have a front side spaced from a front side of an adjacent cold plate to form a gap. The plurality of LED lamps is directed toward the front side of the adjacent cold plate. A wafer lift is positioned to support a periphery of a wafer.

Additional embodiments of the disclosure are directed to wafer cassettes comprising a wall supporting a plurality of cold plates. The wall allows access to a front side of at least some of the cold plates so that a wafer can be positioned adjacent the front side of the cold plates. A reflector is adjacent a back side of at least some of the cold plates. The reflector is separated from the back side of the cold plate by at least one thermal break. A heater is adjacent a back side of the reflector. The heater is separated from the back side of the reflector by at least one thermal break so that there is a gap between a back side of the heater and the front side of an adjacent cold plate. A plurality of lift pins is positioned within the cold plate.

Further embodiments of the disclosure are directed to wafer cassettes comprising a wall supporting a plurality of cold plates. The wall allows access to a front side of at least some of the cold plates so that a wafer can be positioned adjacent the front side of the cold plates. A heater is on a back side of the cold plate so that a back side of the heater is spaced from the front side of an adjacent cold plate to form a gap. An insulator is between the heater and the cold plate.

