Semiconductor Chip Singulation with Laser Functional Layer Severing
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Solution Overview
Problem
Current semiconductor chip singulation methods are inefficient and dependent on the material being severed, often resulting in unreliable and short-lived semiconductor chips.
Innovation Solution
A method involving a composite assembly with a semiconductor layer sequence and a functional layer, where the functional layer is severed using coherent radiation along a singulation pattern, and separating trenches are formed in the carrier to produce semiconductor chips with protected side surfaces, enabling efficient and long-lasting operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional singulation methods are used to sever the substrate material, then the singulation process can be performed, but the efficiency is greatly dependent on the material to be severed and the resulting chips have short lifespan
Solution Approach 1:
The method segments the singulation process into two distinct stages: first severing the functional layer to create initial separations, then forming separating trenches in the carrier to complete the chip separation. This segmentation allows each stage to be optimized independently, achieving both high efficiency and reliability
Solution Approach 2:
The functional layer is severed before forming the separating trenches in the carrier. This preliminary action creates initial separations that guide subsequent trench formation, enabling more efficient and precise singulation while reducing material stress and improving chip lifespan
2Adaptability or versatility
If conventional singulation methods are used, then the substrate material can be severed, but the method is highly sensitive to material properties
Solution Approach 1:
The functional layer acts as an intermediary that is selectively removed first, creating separation paths before the carrier is trenching. This intermediary approach allows the subsequent carrier severing to be less sensitive to carrier material properties, improving both adaptability and precision
Solution Approach 2:
The method changes the physical state and properties of materials through controlled heating and cooling during the singulation process. By temporarily altering material parameters during processing, the method achieves precise singulation across different material types without being constrained by their inherent properties
3Reliability
If the functional layer is not protected during singulation, then the process is simpler, but the side surfaces of chips are exposed to external influences
Solution Approach 1:
A protective layer is applied to the side surfaces of chips before completing the singulation process. This protective layer cushions the chip surfaces against external influences during and after manufacturing, ensuring long-term reliability while adding minimal process complexity
Solution Approach 2:
A thin protective film or coating is applied to the chip side surfaces during the singulation process. This flexible protective layer provides adequate protection against external influences without significantly increasing device complexity or manufacturing difficulty
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method combines high removal rates with material independence and long-term reliability, allowing for precise and efficient production of semiconductor chips with protected surfaces, reducing material sensitivity and extending chip lifespan.
Implementation Method 1
the functional layer is severed by means of coherent radiation, in particular along the singulation pattern
Implementation Method 2
The semiconductor layer sequence is deposited for example epitaxially, for instance by means of sputtering, MOVPE, MOCVD or MBE
Data Source
AI summary
According to the present disclosure, a method for producing a plurality of semiconductor chips is provided with the following steps: a) providing a composite assembly, including a carrier, a semiconductor layer sequence and a functional layer; b) severing the functional layer by means of coherent radiation along a singulation pattern; c) forming separating trenches in the carrier along the singulation pattern; and d) applying a protective layer, which delimits the functional layer toward the separating trenches, on in each case at least one side surface of the semiconductor chips to be singulated. The singulated semiconductor chips each includes a part of the semiconductor layer sequence, of the carrier and of the functional layer.