It's neither thickness nor width
The 5-nanometer chip means that the chip is smaller, the transistor per unit area is denser, and the power consumption is lower. 5 nanometers refers to the characteristic size of the chip. The lowest layer of the chip is the mos tube, the smaller the feature size, the smaller the mos tube produced, which means the higher the integration of the chip, and then the cost is reduced. Under the condition that the chip occupies the same area, the higher the integration, the more functional circuits can be crammed into the chip.
5 nm chip should be width.
The 5-nanometer chip means that the chip is smaller, the transistor per unit area is denser, and the power consumption is lower. 5 nanometers refers to the characteristic size of the chip, and 5nm or 7nm is the width of the transistor, also known as the line width.