PhD after Bachelor’s degree
US Education system encourages students to apply for PhD programs directly after a four year undergraduate degree. If you have a good academic record and genuine interest in research, consider applying for a PhD program while still in the senior/ fourth year of your undergrad degree. PhD at a US University is an intense and intellectually stimulating experience. In the first two years the PhD students take courses like MS students. Subsequent two or three years are mostly spent doing research work.
Those who enroll in PhD programs without a Masters degree have to take more courses before they can graduate. However overall duration is shorter as compared to the time required for separate Masters and doctoral degrees. Many Universities award a M.S. degree after required coursework is completed, check the policy of your target Universities.
Companies do value a PhD degree in the hiring process and there are many research oriented jobs for which those with doctoral degree are preferred. For teaching at any reputable University in the world, PhD degree is required.