IC chip decryption is both mysterious and unfamiliar to everyone. What most people find on the Internet is just some basic concepts. What is chip decryption about? Today we will share with you the actual operation method of chip cracking.
After the packaged chip is tested, it is necessary to connect the two lines for functional testing. At this time, the focused ion beam system can be used to open the passivation layer on the upper layer of the device, exposing the two metal wires that need to be connected, and the ion beam is used to deposit the Pt material. In this way, the two wires are connected together, which can greatly shorten the development time of the chip. This is also a common method for chip cracking.
In the actual operation of cracking the chip, the work of circuit repair and layout verification has the greatest economic benefits. Partial circuit modification can omit the research and development costs of redoing the mask and initial trial production. The time schedule for mass production is absolutely effective, while saving a lot of research and development costs.
So what is the actual cracking operation like? Next, I will explain to you step by step:
Chip circuit modification possible with focused ion beam
(A), (B) Open the passivation layer on the circuit to be connected, (C) Deposit Pt material to connect the two circuits.
The application of focused ion beams to modify chip circuits is actually only one of its functions. Here are some other functions:
Sample processing in situ
It can be imagined that the focused ion beam is like a scalpel with a tip of only tens of nanometers. The secondary electron imaging generated by the ion beam on the surface of the target has nanometer-level microscopic resolution capabilities, so the focused ion beam system is equivalent to a micro-processing table that can be operated under a high-power microscope, and it can be used to sputter on any part Stripped or deposited material.
In-situ electrical performance test
The micromanipulator (KleindiekNanotechnikMM3A) has nanometer-level stepping accuracy, and the rotation of the X-axis and Y-axis is 120 degrees. In the directions of horizontal advance and retreat (X-axis), horizontal rotation (Y-axis) and vertical rotation (Z-axis), The displacement precision is 2, 2.5, 0.2nm respectively. The MM3A micromanipulator consists of piezoelectric motors, tip assemblies, control units and peripheral brackets. A piezoelectric motor consists of a stator and a slider. The piezoelectric motor is made of piezoelectric ceramics with an elongation of 1um to achieve high-precision displacement. The motor driving voltage is -80v~+80v. The driving mode is divided into three levels of fine adjustment mode and coarse adjustment mode. A 12-bit digital-to-analog converter is used , Divide the stepping in the X, Y and Z directions into 4096 steps, so as to realize the precise displacement at the nanometer level. The system can load up to three voltages independently.
Explain: the probe here is also one of the commonly used tools for chip decryption. As for how the complex probe set is used to decrypt the chip, that is a technical matter. So far.
Transmission (TEM) sample preparation
Whether it is TEM or STEM samples, it is necessary to prepare very thin samples so that electrons can penetrate the samples and form electron diffraction images. The traditional method of preparing TEM samples is mechanical slice grinding, which can only analyze large-area samples. A local slice of the sample can be observed by using the focused ion beam. Like the method of cutting the cross-section, the TEM sample is processed by using the focused ion beam from the front and rear directions, and finally leaves a thin area in the middle as the sample for TEM observation.
Section Preparation Observation
Due to the many and complicated processes involved, in the fields of semiconductors, microelectronics and various functional devices, the development and testing of a component will always encounter deviations between actual results and design indicators, failures after device testing, and abnormal logic functions, etc. etc. The intuitive and reliable analysis of the above problems is to prepare the corresponding device cross-section and intuitively characterize the cause of device abnormality from the physical level.
deposition material induction
Metal-organic gas compounds are decomposed by an electron beam or ion beam, allowing material deposition on specific areas of the sample. The materials available for deposition in this system are: SiO2, Pt, W. The deposited graphics are dot matrix, straight lines, etc., and the function of the system to deposit metal materials can be used to modify the device circuit accordingly and change the circuit function.