What was Jack Kilby's net worth at the time of his death? (inventor of the handheld calculator, integrated circuits)

In 1958 Jack kilby laid the foundation for what would eventually become an industry with yearly revenues topping 350 billion dollars.
While working for Texas Instruments, he designed a semi-conductor using a piece of germanium and an oscilloscope that produced a constant sine wave, which ultimately became the first integrated circuit.
Jack kilby himself raised a family and lived a comfortable life.

https://www.forbes.com/2005/06/21/jack-kilby-integrated-circuit-obituary_cx_ah_0621kilby.html


T.R. REID: No, Jack was perfectly comfortable middle class, but he never became a zillionaire out of this. You know what? I don't think he cared. Jack was an engineer. He defined an engineer as a person who solves problems. He knew at the end of his life that he had solved a crucially important engineering problem and for him that was more important than money.