Exhaustive work has been done to fix an optimal high-level process flow that would serve multiple applications. To achieve this, several processing capabilities were implemented into 3 existing processing reactors at Comtpek (1 for substrates up to 4", other for 3", and the last one to process small samples or chips ). We were able to test and validate different combinations of sub-processes (wet and dry cleaning steps, different sources/mechanisms of oxidation, etc), for several types of materials and devices. While obtaining a single process flow that could serve many applications resulted almost impossible, we have identified a combination of processes with a minimum amount of HW components that offers a versatile platform that can be adjusted for multiple target devices. This process consists in:
1.- a Preparation step, that takes place mostly outside the Kontrox processing chamber,
2.- the Passivation step, which includes the proprietary Kontrox step that happens in UHV conditions,
3.- an overcoating step. ALD has been identified as the most promising overcoating method for the application areas under scope.
This main process will set the technical specifications for the pilot line. The applications and materials will determine the particular process parameters, what type of preparation step is needed, what particular chemicals etc. Additionally, the Kontrox process might need to be implemented in different ways.
We have defined 2 clear process flows, one for µLEDs / power electronics chips on full wafer scale, and another for passivation of edge emitting lasers, applied to final chip structures.
This process flows and processing parameter ranges have been the basis for the list of technical requirements for the pilot line.
A pilot line has been designed and built to implement Kontrox(tm) technology in substrates of up to 200mm based on the process requirements identified in the first half of the project period. It integrates via high vacuum connection the Kontrox reactor, with Plasma Enhanced Atomic Layer Deposition system (PE-ALD) and also with a inert atmosphere glove box with wet etching capabilities. With this pilot line we are able to develop and perform complex passivation stacks and solutions for multiple semicopnductor chip structures.
The process has been validated in 200mm substrates for µLEDs and for III-N wafers for RF and power electronic applications
The Kontrox reactor has been designed and optimized to be as energy efficient as possible, trying to reduce the high energy consumption levels that are associated to these type of processes (passivation, thin film growth, etc)
