Precitec local:
Select Language:
Search
반도체 산업
적용 > 광학 측정 기술 > 반도체 산업

웨이퍼의 인라인 품질 검사

 반도체 산업에서의 적용 사항들은 마이크로미터 범위의 측면 해상도와 마이크로미터 미만 범위의 고도 해상도를 요구합니다. 인라인 품질 검사에서 센서들은 웨이퍼 두께를 측정하고, 마스크 제작에서 반도체 구조를 규명하고, 결합들을 점검합니다. 그밖에 센서들은 투명 코팅들을 측정하고, 래커칠 두께를 규명하고, 기계적, 화학적 제거 공정을 실시간으로 감시합니다. CHRocodile-센서들은 산욕뿐만 아니라 초고도 진공에서도 신뢰성 있게 측정합니다.

적용
제품 계열 CHRocodile 2 IT
웨이퍼를 접촉 없이 측정

웨이퍼와 태영 전지의 매우 간편하고 동시에 고도로 장밀한 거리 및 층 두께 측정을 CHRocodile IT 제품 계열의 센서들이 합니다. 이 광학 센서들은 접촉 없이 측정 헤드 하나만으로 최대 1 mm 두께의 실리콘을 측정할 수 있습니다. 테두리 범위까지 두께를 정확하게 규명하는 것은 최고의 제품 품질을 위해 매우 중요합니다. CHRocodile IT는 특히 작은 측정점을 통해 그것을 보장합니다. 그러나 CHRocodile IT 계열 센서들은 훨씬 더 많은 것을 할 수 있습니다: GaAs 웨이퍼, 시각적으로 투명하지 않은 포일 및 다층 시스템 측정. 당사 센서들의 튼튼하고 간단한 구성은 직접 생산 공정 편입을 가능케 합니다. 물론 실험실에는 비용 효과적이고 동시에 고도로 정밀한 층 두께 측정용 장비들이 제공됩니다.

CHRocodile 2 IT DW
매우 오염된 웨이퍼의 두께 측정

Both high and low doped wafers can be measured to determine the thickness with interferometric measuring systems in the infrared range. Other quality criteria are bowing and warping that are taken into account particularly with very thin wafers. The structures applied in layers can distort wafers. The level of distortion can be determined very accurately with distance sensors.

CHRocodile CLS
Chip handling: Chip bonding, OLED & LED chips

Metallic OLED display masks can be measured with the line sensor CHRocodile CLS. Imperfections can be reliably detected here. The sensors are also suitable for the ever more compact LED chip packages for high levels of illumination and small form factors, such as is common for LED background lighting and LC screens. Both cutting profiles and also topographies can be created. When the chips are assembled, Precitec Optronik sensors determine the correct position of chips.

Often individual LED are no longer used but highly integrated chips with a large number of light diodes. When testing these optical chips, contact-free measuring distance sensors are already used to a large extent today. These can measure the height of the LED (Z co-ordinates).

CHRocodile CLS
Through Silicon Via (TSV)

Through Silicon Via is a mainly vertical electrical metal connection by a wafer. Here a vertical pile of thinned out individual chips is connected through using small copper structures. After the etching process these protrude a little above the silicon and are known as bumps. The TSV structures before filling – which are holes with a high aspect ratio – and the bumps that occur after filling can themselves be measured with Precitec sensors. The height of the bumps over the silicon structures and the depth of the TSVs are required.

CHRocodile 2 IT TW
Circuit board layer thicknesses

The layer thicknesses of silicon casting compounds or solder resist can be measured. Basically there are two different measuring procedures here, chromatic measuring and interferometric measuring. Silicon casting compound can be measured both chromatically and interferometrically. The layer thickness of coloured solder resist can also be measured with the interferometric measuring method. Here the interferometric method has slight advantages over chromatic measuring because it can tolerate a measuring distance deviation of a few millimeters. A 3D measuring device is required if necessary to adjust the measuring distance so that the measured surface is within the permissible operating range of the measuring head.

CHRocodile CLS
Measuring glue beads

In the case of glue beads, they often still rely on a visual inspection. It is important that the glue bead trail is continuous and constant. Several parameters are used as quality criteria that can be determined by optical measuring systems. The glue bead must run in the middle with regard to other structures. Undesirable accumulations of material at the start and end point of the bead can be detected. Even gaps can be detected.

CHRocodile LR
Encapsulation of chips with dispensing machines (dam and fill procedure)

With procedures called dam and fill, first of all a dam made of a viscous cast compound is set up on the circuit board that completely surrounds the chip. Then a dispensing machine dispenses a material to the inner area of the dam that has a low as possible viscosity. This surrounds the delicate structures and wires completely until the component is completely covered. Precitec chromatic confocal sensors measure the height of these chip cast compound dams without touching them accurately to within a few microns. This ensures that the dam height is sufficient for the subsequent cast of the inner area and the protective paint does not run over unprotected areas. The speed of the measuring procedure enables a 100% check of all components manufactured. As a result, casting components is also suitable for high volume, fully automatic manufacturing.

제품으로
CHRocodile MI5
Quality assurance measurements in the manufacturing process of semiconductors

Many manufacturing processes are dealing with the removal of layers. For example, during wet etching, solid material is converted into liquid compounds with help of a chemical solution. To check the process optical sensors are used. Sensors are used as well to check rinsing processes that allow contaminants to be removed from the wafer surface.

© 2019 Precitec Group