Cree announces the relationship between the defect density of SiC substrate and the chip yield

The large SiC motherboard manufacturer CREE (CREE) SiC in the international society "in the seventh session of the European Conference on silicon carbide and related materials (ECSCRM)", "Defect Control in SiC Manufacturing", SiC floor characteristics in respect of the company's speech (speech number: Tu3-2). In this paper, the relationship between the yield of the chip and the crystalline defects and the hollow through defects (micro tubes) is introduced. The various dislocation densities of the 100mm (about 4 inch) substrate are also reported. CREE has begun to supply almost no microtubules with a diameter 100mm "no microtubule" backplane.

The company with N type 4H-SiC plate has been put into operation with 100mm as an example to introduce the chip yield, on the surface of the bottom plate has 165 standard crystal defects and only 21 crystal defects of low defect products were compared. When making 2mm Square chip chip yield, the standard is 94.1%, low defect product is 99.2%. The chip size is large, standard and low defect rate of finished product difference is bigger, 3mm square chip, the standard is 87.8%, low defect product is 98.2%, 5mm square chip, the standard is 73.3%, low defect product is 95.8%.

In addition, also with the diameter of a 100mm epitaxial layer and N type 4H-SiC plate products as an example, the standard has 184 crystal defects of the epitaxial layer surface and a total of only 63 low defect products, compare when manufacturing the chip yield. 2mm Square chip yield, the standard is 93.2%, low defect product is $98.1%. 3mm square chip yield, the standard is 85.5%, low defect products for the, 5mm square chip yield, the standard is 68.8%, low defect product is $90.8%.

The relationship between the density of microtubules and the yield of the chip is evaluated by taking the N 0.7 /cm2 with a density of only 100mm and the diameter of the tube as an example. 2mm Square, no microtubule chip yield of 96%, 5mm square is, 10mm square is 65%.

In addition, various types of dislocation density of n 4H-SiC backplane "1C dislocation" and "Basal Plane dislocation" are also reported. The diameter of 100mm R & D products, the dislocation density of 1C dislocation average of 425 /cm2, diameter of about 75mm (3 inches) of R & D products for the /cm2 of 175. Basal Plane dislocation, the diameter of 100mm products for 1550 /cm2.

Source: Nikkei BP